1.1.

1 compare the five generations of computer;

First generation of computers Second generation of
(1940-1956) computers (1956-1963)
Speed Slowest Faster
Memory Least Bigger
Size Main frame Smaller main frame
Cost Most expensive Cheaper
Reliability Least reliable More reliable
Power consumed Most Less
Heat generated Most Less
Input Punched cards Punched cards, magnetic
tapes/ disks
Output Printouts Printouts
Primary internal Magnetic drums Magnetic core
storage medium
Programming Machine language Assembly language,
language high-level language
FORTRAN.
Operating system Batch processing Batch processing and
multi-programming operating
systems
Use Scientific, research Commercial productions,
scientific and engineering
analysis and design.
Examples Electronic numerical integrator and IBM 7094, IBM 1401
calculator (ENIAC), universal
automatic computer (UNIVAC)
Third generation of computers Fourth generation computers
(1963-1971) (1971-present)
CPU technology IC chips, integrated circuit, Microprocessor
semi-conductor chips
Speed Faster Faster
Memory Bigger Biggest
Size Mini Desktop
Cost Cheaper Cheapest
Reliability Reliable More reliable
Power consumed Less Least
Heat generated Less Least
 Input Keyboard, magnetic tape Pointing devices, keyboard,
optical scanning
Output Monitor, printer Monitor, printer
Primary internal Large magnetic core, Semiconductor memory
storage medium magnetic/disk. (RAM, ROM)
Programming High-level languages such as High-level languages like C,
language FORTRAN, COBOL and BASIC C++ and pascal.
Operating system Time-sharing, real-time, Time-sharing, real-time and
multi-programming operating distributed operating system.
system
Use scientific, business General use
Examples IBM system/360, IBM 7094, IBM thinkpad series, HP
IBM 1401 pavilion series, Dell inspiron
series, apple’s Macbook air
series.

1.1.2 describe the types of computer on the basis of:

a. purpose (general, special)
b. technology (analog, digital, and hybrid)
GENERAL PURPOSE:
● These computers can process variety of tasks. These computers can store and execute
different programs in their memory.
● Desktops, laptops, tablets and smartphones are examples.
SPECIAL PURPOSE:
● These computers are designed to perform specific tasks. Special purpose computers
repeatedly perform single job more efficiently. They are also known as dedicated
computers. These computers are useful in traffic lights control system, navigational
system, aviation, weather forecasting, satellite tracking and ATMs.
ANALOG:
● Analog computers represent and process data by measuring quantities such as voltage
and current to solve a problem.
● They work on supply of continuous signals as input and display output simultaneously.
● Analog computers are special purpose devices, designed to perform single specific task.
● Mostly these devices are used in engineering and scientific applications.
● The accuracy of analog computers is low but they are faster in speed as compared to
digital computers.
● They mainly consist of electrical devices such as resisters, capacitors, transistors,etc.
DIGITAL:
● Digital computer works with digits. Everything in a digital computer is represented with
binary digits 0s and 1s. it manipulates them at very fast speed. Data and instructions are
fed into the digital computer through an input device in the form of 0s and 1s. the
computer performs calculations on data according to the instructions given in a
computer program. The results of calculations are displayed on monitor or printed on
printer.
● Digital computers can store and process large amount of information at high speed.
● The results produced by digital computers are reliable and accurate.
● Digital computers are general-purpose computers, used in various fields.
HYBRID:
● Hybrid computers are the combination of analog and digital computers. They combine
the characteristics of both analog and digital computers.
● Hybrid computers are mainly used for scientific applications. These computers are used
in spaceships, missile systems, scientific research, hospitals and for controlling industrial
processes.
1.1.3 describe the conventional classification of digital computers, i.e. supercomputer,
mainframe computer, minicomputer and microcomputer;
SUPERCOMPUTERS:
● Supercomputers are the largest and the most powerful computers.
● Super computers have been used for scientific research and engineering applications
that must handle very large databases and do a great amount of computation.
● These computers are very expensive.
● Their speed is measured in TIPS (trillion instructions per second).
● Supercomputers generally run one program at a time, as fast as possible.
● Supercomputers are used for specialized situations in which immense processing speed
is required.
MAINFRAME COMPUTERS:
● Mainframe computers were developed in the early 1940s.
● Mainframe computers are powerful multi-user and multi-processors computers.
● They can process huge amount of calculations at very high speed.
● Mainframes are also very expensive and require a lot of technical expertise to be
installed and operated.
● They are used in banks and many large business organizations where several users work
simultaneously.
● These computers can execute more than trillion instructions per second (TIPS).
 ● Mainframes are used to perform large processing tasks for businesses.
● Mainframe computers are typically located in climate-controlled data centers and
connect to the rest of the company computers via a computer network.
● Today’s mainframes are sometimes referred to as high-end servers or enterprise class
servers.
MINICOMPUTERS/ midrange servers:
● A minicomputer is a medium-sized computer used to host programs and data for a small
network.
● A minicomputer is usually located in an out-of the way place and can serve many users
at one time. Users connect to the server through a network, using their desktop
computer, portable computer, etc.
● Minicomputers are often used in small to medium-sized businesses.
● Minicomputer was introduced in the 1960s when IC chips were introduced.
● These computers can execute billions of instructions per second (BIPS).
MICROCOMPUTER:
● Microcomputers are the smallest and the low cost computers.
● These computers are most commonly used in homes and offices.
● Microcomputer was introduced in 1970s when microprocessor was developed. A
microprocessor is a single chip that controls the operations of the entire computer
system.
● Modern microcomputers have large storage capacity and they can execute millions of
instructions per second (MIPS).
● A variety of software is available for use in these computers.
1.3.1 compare input devices, i.e. keyboards, mouse, light pen, joystick, trackball, touchpad,
scanner, sensors, magnetic ink character reader (MICR), barcode reader (BCR), optical mark
reader (OMR), optical character recognition (OCR) reader, microphone, and digital camera;
1. Keyboard: A keyboard is a standard input device that allows users to input text and
commands by pressing keys. It is a widely used input method for typing and interacting
with computers.
2. Mouse: A mouse is a pointing device that enables users to move a cursor on the screen
and select objects by clicking buttons. It provides a graphical interface for navigating and
interacting with applications.
3. Light Pen: A light pen is a handheld device that allows users to interact with a screen by
touching the display surface. It is typically used for drawing or selecting objects on a
monitor.
 4. Joystick: A joystick is a lever-like input device primarily used for controlling movement in
gaming and flight simulation applications. It provides analog input for precise directional
control.
5. Trackball: A trackball is a stationary pointing device that allows users to move a cursor by
rolling a ball with their fingers or palm. It provides similar functionality to a mouse but
with a different form factor.
6. Touchpad: A touchpad is a flat, touch-sensitive surface found on laptops and some
desktop keyboards. Users can move the cursor by sliding their fingers on the touchpad.
7. Scanner: A scanner is used to convert physical documents or images into digital formats.
It captures images or text and transfers them to a computer for further processing or
storage.
8. Sensors: Sensors are input devices that detect and measure physical phenomena such as
temperature, pressure, light, motion, or proximity. They convert these measurements
into electrical signals for use in various applications.
9. Magnetic Ink Character Reader (MICR): MICR is a technology used for reading characters
printed with magnetic ink. It is commonly used in banking systems to process checks and
other financial documents.
10.Barcode Reader (BCR): A barcode reader scans and decodes barcode symbols. It is widely
used in retail, inventory management, and logistics for quickly and accurately capturing
product information.
11.Optical Mark Reader (OMR): OMR devices are designed to detect and read marked areas
on paper forms, such as checkboxes or bubbles. They are commonly used in surveys,
exams, and voting systems.
12.Optical Character Recognition (OCR) Reader: OCR technology is used to convert printed
or handwritten text into machine-readable text. OCR readers can extract text from
documents, making it searchable or editable.
13.Microphone: A microphone converts sound waves into electrical signals. It is used for
audio input, such as voice recording, voice commands, or communication in applications
like voice recognition or video conferencing.
14.Digital Camera: A digital camera captures still images or videos and stores them in digital
formats. It is commonly used for capturing visual input, such as photographs or video
footage.
1.3.2 identify the use of types of sensors, i.e. temperature, moisture, light, infra-red,
pressure, sound/acoustic, gas, Ph;
Sensor Application
Temperature ● Control a central heating system
 ● Control a chemical process
● Control the temperature in a greenhouse
Moisture ● Control the moisture levels in the soil in a greenhouse
● Control the humidity levels in the air in a greenhouse
● Monitor dampness levels in an industrial application (e.g. monitor
moisture in a point spray booth in a car factory)
Light ● Switch street lighting on at night and off during the day
● Control light levels in a greenhouse
● Automatically switch on a car’s headlights when it gets dark
Infra-red ● Turn on the windscreen wipers on a car automatically.
● Detect intruders in a burglar alarm system
● Count people entering/leaving a building
Pressure ● Detect intruders in a burglar alarm system
● Weigh things (e.g. check the weight of a vehicle)
● Monitor a process where gas pressure is important
Sound ● Pick up noise levels (e.g. footsteps) in a burglar alarm system
● Detect the noise of liquids dripping in a pipe
Gas ● Monitor pollution levels in a river or in the air
● Measure oxygen and carbon dioxide levels in a greenhouse
● Check for carbon dioxide leaks in a power station
Ph ● Monitor/ control acidity/alkalinity levels in the soil in a greenhouse
● Pollution/ environmental monitoring in rivers

1.3.3 explain diagrammatically (block diagram) the components of the computer system, i.e.
input unit, output unit, storage unit/memory unit, control unit and arithmetic logic unit;
1.3.4 describe the function of components of computer system mentioned in SLO 1.3.3;
Input unit The input unit is responsible for accepting data and instructions from
external sources, converting it into a format that the computer can
understand and process and transmitting the converted data to the
appropriate components within the computer system, such as the
memory unit or the processor.
Output unit The output unit receives data from the memory unit or the processor,
converts the output data into a suitable format for transmitting and
sending the converted output to various output devices.
Storage/memory The storage unit or the primary/main storage of a computer system is
unit designed for storing data during before and after processing.
Control unit Control unit is responsible for controlling the transfer of data and
instructions among other units of a computer. It synchronizes the
operations within the system for smooth running.
Arithmetic logic ALU is the part of the computer that performs all the calculations and
unit (ALU) comparisons. It consists of arithmetic and logic unit. Arithmetic unit
performs all the arithmetic operations such as addition, subtraction,
multiplication and division. Logic unit performs logical operations which
include comparisons of numbers or alphabets.

1.3.5 compare primary and secondary storage devices on the basis of location with respect
to central processing unit (CPU), cost, storage capacity, average access time, direct/ indirect
data processing, means of storing information such as semiconductor, magnetic disks,
magnetic tape and optical discs;
Characteristics Primary /main/ internal Secondary/external storage
memory
Location with Primary storage devices are Secondary storage devices are located
respect to the located closer to the CPU. They farther from the CPU. They are
CPU are directly accessible by the connected to the system through buses
CPU, allowing for faster data or interfaces and have slower data
access and processing. access compared to primary storage.
Cost Expensive Less expensive
Capacity Primary storage devices have Secondary storage devices offer larger
smaller storage capacities storage capacities, allowing for
compared to secondary storage. long-term storage of data, programs,
They typically store the data and files. They can store a vast amount
and instructions that are of data that is not immediately needed
currently being processed by for processing.
the CPU.
Average access Nanoseconds or microseconds Milliseconds or seconds
time
Direct/indirect Primary storage enables direct Secondary storage devices are primarily
data processing data processing. The CPU can used for indirect data processing. Data is
directly access and manipulate first transferred from secondary storage
data stored in primary storage. to primary storage before it can be
processed by the CPU.
Means of storing Semi-conductor Magnetic disks, magnetic tape and
information optical disks
Examples Random access memory (RAM), Hard disk drive (HDD), magnetic tape,
cache memory optical disk(CDs, DVDs)

1.3.6 differentiate between the types of primary memory, i.e. random access memory (RAM)
and read only memory (ROM);
RAM (random access memory) ROM (read-only memory)
Volatile memory: Its contents are lost when Non-volatile memory: its contents are
the computer is powered off or restarted. It retained even when the computer is powered
requires a constant supply of power to retain off.
data.
It is possible to both read data from memory Only reading of data from memory is possible
and write data into memory
Temporary storage Permanently storage
Used in normal operations of a computer Used for start-up process of computer
Writing data is faster hence faster memory Writing data is slower hence slower memory
RAM is costly ROM is cheaper
Instructions are written into the RAM at the Instructions are written into the ROM at
time of execution manufacturing time.
Instructions in RAM change continuously as It is not possible to write new information or
new programs are executed and new data is new instructions into the ROM.
processed.
It can hold a large amount of data as It can only store small amount of data
compared to ROM (around in GBs) and large permanently (around 4MB per chip or more
in size per chip) and small in size
The data in RAM can be modified easily The data in ROM can never be modified
RAM is directly accessed by the processor ROM can not be directly accessed by the
processor since it is transferred into RAM
where its executed by the processor
Uses a lot of power Uses very little power
Used in CPU cache and primary memory Used in firmware and microcontroller
Example: SRAM and DRAM ROM: PROM, EPROM and EEPROM

1.3.7 describe cache memory and its three types diagrammatically;

Cache memory: Cache memory is a high-speed buffer/memory kept in between processor and
RAM to increase data execution speed and computer performance. It stores program
instructions and data that are used repeatedly.
L1 cache:
● Primary cache or internal cache. A cache memory that is built directly in to the
processor, it’s the smallest cache and operates at the same speed as the CPU, its also the
fastest cache.
● Each core in CPU has their own L1 cache memory. Sizes range from 8KB to 256KB. It
stores CPU’s recently accessed info.
L2 cache:
● Its also composed of SRAM. Its also called secondary cache or external cache. Larger
than L1 but smaller than L3 cache. Slower than L1 but faster than L3. Each core in the
CPU has its own L2 cache memory. It stores the data that is not stored in the L1 cache. In
other words, if the CPU cannot find the data it is looking for in the L1 cache, it checks the
L2 cache. It is usually 64KB to 2MB in size.
L3 cache:
● Called external cache. L3 cache is specialized memory developed to improve the
performance of L1 and L2. L3 caches are found on the motherboard rather than the
 processor. It is kept between RAM and L2 cache. Largest cache. Slowest cache than L1
and L2. All the cores in the CPU share the same L3 cache memory. It stores data that is
not stored in L1 and L2 cache. In other words, if the CPU cannot find the data it is
looking for in L1 and L2 cache, it checks L3 cache. L3 cache has more than 3MB of
storage in it.

1.3.8 describe the two types of secondary storage devices, i.e. hard disk drive and universal
serial bus (USB) flash drive;
HARD DISK DRIVE:
● A hard disk is a magnetic storage device used to store computer data. It has storage
capacity of hundreds of gigabyte (GB). It is non-volatile, permanent, long term storage.
● The hard disk drive consists of circular glass platters (disks). Both surfaces of the platters
are coated with a magnetic medium. Information is stored magnetically on both sides of
each platter. The platters are attached to a spindle holding them parallel to each other
with equal gap. All the platters rotate together at high speed. Each platter has two tiny
read/write heads for writing data to reading data from both surfaces of the platter.
● The surface of platters is divided into a number of evenly spaced concentric circular
tracks. Bits are stored on the magnetic surface in spots along tracks. Tracks are divided
into sections called sectors. Two or more adjacent sector form cluster. The set of all
tracks at a given radius on all surfaces are known as cylinders.
● The hard disks are manufactured in very clean environment. They must be kept dust
free. Dust particles can create scratches on the surface of the platters and damages the
data stored in it. The storage capacity of modern hard disk is a terabytes or more.
USB FLASH DRIVE (universal serial bus):
● It is a plug and play portable storage device that uses flash memory (NAND type). Flash
memory means they use a non-volatile memory chip to store digital content or
information. It consists of standard type-A USB connection allowing plugging in the port
 of computer. It is also known as USB memory. It is very fast in operation. Its storage
capacity is 128 MB to currently 2TB, till now.

1.3.9 compare the types of output devices, i.e. speaker, Liquid Crystal Display (LCD), Light
Emitting Diode (LED) display, printers and their types, plotter, actuators and their types,
cutters;
Output devices: Output devices are used to display text, graphics, and images on the monitor
or to print information on paper. Information displayed on monitor is known as softcopy and
anything printed on paper is known as hardcopy or printout. Commonly used output devices
are monitor, printer, plotter and speaker.
Speaker:
● Function: Speakers are used to produce audio output, allowing users to hear sound,
music, and other audio elements generated by the computer system.
● Output Type: Sound waves or vibrations that are converted into audible sound.
● Common Types: Built-in speakers, external speakers, surround sound systems,
headphones, etc.
Liquid crystal display (LCD):
● Function: LCD displays are commonly used for visual output, providing a clear and
vibrant display of images, text, and graphics.
● Output Type: Visual output using liquid crystals that can be manipulated to create
images.
● Common Types: LCD monitors, laptop screens, mobile phone screens, etc.
Light emitting diode (LED) display:
● Function: LED displays are similar to LCD displays but use light-emitting diodes to provide
backlighting, resulting in improved brightness and energy efficiency.
● Output Type: Visual output using LED technology for backlighting.
● Common Types: LED monitors, LED TVs, digital signage displays, etc.
Printers and their types:
● Function: Printers produce physical copies of digital documents or images on paper or
other printable materials.
● Output Type: Printed text, images, or graphics on paper or other media.
 ● Common Types: Inkjet printers, laser printers, thermal printers, dot matrix printers, 3D
printers, etc.
Impact printer:
● Impact printer uses electro-mechanical mechanism which causes the character shape to
strike against the paper and leave an image of the character on the paper. The printing
speed varies from 50 to 500 cps. Their printing is very cheap but print quality is poor.
They produce a lot of noise while printing. These printers are still in use for printing
invoices, bank statements, utility bills, etc. example: dot matrix printer
Non-impact printer(inkjet and laser):
● Non-impact printer prints without striking the paper.
● Inkjet printer stores ink in cartridge and sprays on paper through fine nozzles on the
print-head. Inkjet printers are used in all sectors such as homes and simple businesses.
● Laser printer uses technology similar to photocopying machine. Laser printer is more
expensive, faster and has very high print quality compared to inkjet printer. Laser
printers are perfect for large scale businesses.
Plotter:
● Plotter is an output device used for printing engineering drawings, machine parts,
building designs, maps, charts and panaflexes etc. on large size papers/sheets. It is more
expensive than printer. There are two types of plotters, that is, ink plotter and pen
plotter. Ink plotter is used for printing images whereas pen plotter is used for printing
engineering drawings, machine parts, building designs, etc. plotter is a slow output
device but it’s printing quality is good.
Actuators and their types:
● Function: Actuators are output devices that produce physical movement or control
mechanisms based on computer instructions.
● Output Type: Mechanical movement, vibration, or physical response.
● Common Types: Motors, solenoids, servo motors, pneumatic actuators, hydraulic
actuators, etc.
● Linear actuators: a linear actuator moves a body or mechanism in a linear direction. In
other words, they provide push-pull motion to a rigid body or mechanism.
● Rotary actuator: rotary actuators move a mechanism in a circular motion.
Cutters:
● Function: Cutters are output devices used for cutting or trimming materials according to
computer-controlled instructions.
● Output Type: Precise cutting or trimming of materials.
● Common Types: Vinyl cutters, laser cutters, CNC routers, paper cutters, etc.

1.3.10 differentiate between serial and parallel ports;

Serial ports Parallel ports
Transfer one bit at a time via one wire, Transfer group of bits (8 or 16 or 32 or 64) at a time
one after other via group of wire
Short and long distance communication Short distance communication
Data transmission is slow. Data transmission is fast.
Slower devices are connected with serial Faster devices are connected with parallel port .
port mostly
Male Port Female Port
Slower than parallel Faster than serial
Support longer cable length – Max 10 Support short cable length – Max 6 feet
feet
9 pins 25 pins
Less Costly More Costly
Data can be transmitted in More time Data can be transmitted in less time
Data Congestion take place No , Data Congestion
No , crosstalk problem Crosstalk create interference between the parallel
lines.

1.4.1 differentiate between data and information;

Data Information
Data is raw fact Processed data
Meaningless Always meaningful
Understanding is difficult Understanding is easy
Data may not be in order Information should be in order
Input to any system may be treated as data. Output after processing system is information.
Data is not significant to a business and of Information is significant to a business and
itself. itself.
Data does not help in decision making Information helps in decision making.

1.4.2 describe the basic operations of the data processing cycle using block diagram;
a. input operation
b. processing operation
c. storage operation
d. output operation;
Data processing: Data processing is simply the conversion of raw data to meaningful
information through a process.
Step 1 Input operation: correct output result depends on the input data. It is the step of
feeding/entering data to the computer by using input devices.
Step 2 processing operation: in this step the computer processes the data which is fed in the
first step. The processing is carried out by the device known as the central processing unit
(CPU). The CPU performs arithmetic and logical operations.
Step 3 output operation: in this step the processed data is presented through output devices
(monitor, printer). Users view the output, understand it, and make decisions on the basis of
their understanding.
Step 4 storage operation: the last step of data processing cycle is storage, where data is stored
for further use. This allows for quick access and retrieval of information whenever needed.

1.5.1 differentiate between the types of software, i.e system software and application
software;
System Software Application Software

System Software maintains the system resources Application software is built for specific
and gives the path for application software to run. tasks.

Low-level languages are used to write the system While high-level languages are used to
software. write the application software.

It is general-purpose software. While it’s a specific purpose software.

Without system software, the system stops and While Without application software system
can’t run. always runs.

System software runs when the system is turned While application software runs as per the
on and stops when the system is turned off. user’s request.

Example: System software is an operating system, Example: Application software is

etc. Photoshop, VLC player, etc.

System Software programming is more complex Application software programming is

than application software. simpler in comparison to system software.

The Software that is designed to control, A set of computer programs installed in the
integrate and manage the individual hardware user’s system and designed to perform a
components and application software is known as specific task is known as application
system software. software.

A system software operates the system in the Application software runs in the front end
background until the shutdown of the computer. according to the user’s request.

The system software has no interaction with Application software connects an

users. It serves as an interface between hardware intermediary between the user and the
and the end user. computer.

System software runs independently. Application software is dependent on

system software because they need a set
platform for its functioning.

System software: System software is the set of programs that manage and control the basic
functions of a computer system. It includes the operating system, device drivers, utility
programs, and other system-level software. The primary purpose of system software is to
provide a platform for running application software and to manage hardware resources such as
memory, processors, and storage devices.
Types of system software:
1. Device drivers: Device drivers are software programs that allow the operating
system to communicate with hardware devices, such as printers, scanners, and
graphics cards. Device drivers act as translators between the hardware and the
operating system, allowing the two to work together seamlessly.
2. Utility programs: Utility programs are system software tools designed to perform
maintenance and optimization tasks, such as disk defragmentation, system
backups, and virus scans. Examples of popular utility programs include antivirus
software, disk cleanup tools, and system optimization software.
3. Language translators/processors: Language translators/processors are used to
convert high-level programming languages, such as Java, C++, and Python, into
machine code, which is a low-level language that can be executed by the
computer's CPU. There are three main types of language translators/processors:
● Compiler: a compiler is a program that translates the entire source code of

a program written in a high-level language into machine code. Compiler

translates whole program into machine language at once and makes a
separate object file for the translated program for further execution. The
 resulting machine code can then be executed directly by the computer's
CPU.
● Interpreter: An interpreter is a program that translates and executes each
line of code in a program written in a high-level language one line at a time.
The interpreter translates each line of code into machine code and executes
it immediately, without creating a separate machine code file.
● Assembler: An assembler is a program that translates assembly language
code, which is a low-level language that closely resembles machine code,
into machine code. Assembler is typically used for programming low-level
hardware devices, such as microcontrollers.
4. Operating system: The operating system (OS) is the most fundamental type of
system software. It is responsible for managing and coordinating the activities and
sharing of resources of the computer system. Examples of popular operating
systems include Microsoft Windows, macOS, and Linux.
Application software: Application software, on the other hand, is designed to perform specific
tasks or solve specific problems for end-users. It includes programs such as word processors,
spreadsheets, database management systems, web browsers, and multimedia players.
Application software is typically written to run on top of a particular operating system and
utilizes the system software to interface with the computer hardware.
Types of application software:
1. Word processors: Word processors are software applications that allow users to
create, edit, and format text documents. Some popular examples of word
processors include Microsoft Word, Google Docs, and Apple Pages. Word
processors typically include tools for formatting text, inserting images, and
creating tables.
2. Spreadsheets: Spreadsheets are software applications that allow users to
organize, analyze, and manipulate numerical data. Some popular examples of
spreadsheet software include Microsoft Excel, Google Sheets, and Apple
Numbers. Spreadsheets typically include tools for creating formulas, charts, and
graphs.
3. Communication: Communication software includes various applications that
allow users to communicate with each other over the internet. Examples of
communication software include email clients, instant messaging applications,
and video conferencing software.
4. Entertainment: Entertainment software includes applications designed for leisure
activities such as gaming, streaming movies, or listening to music. Some popular
 examples of entertainment software include gaming platforms like Steam and
consoles like Xbox, streaming platforms like Netflix and Spotify.
5. Presentation: Presentation software is used to create multimedia presentations
that can include text, images, audio, and video. Examples of presentation software
include Microsoft PowerPoint, Google Slides, and Apple Keynote. Presentation
software typically includes tools for creating slideshows, adding animations and
effects, and embedding media.
6. Database management: Database management systems (DBMS) are software
applications that allow users to store, organize, and manage large amounts of
data. Some popular examples of DBMS include Oracle, MySQL, and Microsoft SQL
Server. DBMS typically include tools for creating and managing databases, running
queries, and analyzing data.
7. Desktop publication: Desktop publishing software is used to create and publish
printed or digital materials such as books, magazines, and brochures. Some
popular examples of desktop publishing software include Adobe InDesign,
Microsoft Publisher, and QuarkXPress. Desktop publishing software typically
includes tools for laying out text and images, formatting text, and creating
graphics.
1.5.2 differentiate among the following types of system software:
a. operating system
b. device drivers
c. utility programs
d. language processors;
Type of Description
System
Software

Operating The main system software that manages and controls the computer's
System hardware and other system resources. It provides a platform for running
application software and manages tasks such as memory management, file
management, and security. Examples include Windows, MacOS, and Linux.

Device Drivers Software that allows the operating system to communicate with hardware
devices such as printers, scanners, and sound cards. Device drivers translate
the instructions from the operating system into a language that the
hardware device can understand.
Utility Programs that perform specific system tasks, such as disk cleanup, virus
Programs scanning, and file compression. They are often included with the operating
system or can be downloaded separately. Examples include antivirus
software, backup and recovery software, and system optimization tools.

Language Software that translates source code written in a programming language

Processors into machine code that can be executed by the computer's processor. There
are three types of language processors: compilers, interpreters, and
assemblers. Compilers translate the entire program at once, interpreters
translate and execute one line at a time, and assemblers translate assembly
language into machine code.

1.5.4 differentiate among open source software, shareware and freeware;

Freeware Shareware Opensource software
• Free available in market ● Not Free, based on ● Free, available in
• Source Code not payment. market
available in market ● Source Code not ● Source code available in
• Full version, unlimited
available market.
• Users can not modify
source code. ● Trial Version, free for a ● Users can modify
• Unlimited distribution. period source code
• Can't sell ● Users can not modify ● Unlimited use
source code ● Unlimited distribution
● Limited use ● Examples: Linux, Libre
● Unlimited distribution office, Firefox
2.1.1 define operating system (OS);
An operating system is a type of software that manages and controls the hardware and other
resources of a computer. It acts as the interface between the user and the computer, making it
easier for users to interact with the machine. Without an operating system, a computer cannot
function properly. It controls how programs and applications run on the computer, manages
memory, storage, and input/output operations, and provides security features to protect the
computer from malware and other threats. Examples of operating systems include Windows,
macOS, Linux, and Android.
2.1.2 describe the functions of OS, i.e. memory management, I/O management, files
management, resource management, users management and process management;
Memory management: Operating systems manage the computer's memory by allocating
memory to applications and processes as needed and freeing up memory that is no longer
needed. This ensures that the computer runs smoothly and efficiently.
Input/output (I/O) management: Operating systems manage the input and output operations
of a computer, including tasks like reading data from storage devices, displaying graphics on
the screen, sending data to printers or other devices and using I/O controller to manage and
coordinate the operation of all the input/output devices.
File management: File management system is part of OS that organizes, stores and keeps track
of computer files and folders. Operating systems manage files and directories, including
creating, deleting, and moving files, as well as providing access controls to ensure that only
authorized users can access sensitive data.
Resource management: Operating systems allocate system resources such as CPU time,
network bandwidth, and disk space. This ensures that each process and application running on
the computer gets the resources it needs to run efficiently.
User management: Operating systems provide a way to manage users and their permissions
on a computer. This includes creating and deleting user accounts, setting permissions for files
and directories, and managing user sessions.
Process management: A process in execution needs resources like processing resource,
memory and I/O resources. Operating system must allocate resources to processes, enable
processes to share and exchange information, and protect the resources of each process from
other processes.

2.1.3 differentiate among the following three types of user interfaces provided by OS:
a. command line interface (CLI), e.g. DOS and UNIX
b. menu driven interface (MDI), e.g. Novel
c. graphical user interface (GUI), e.g. macintosh, linux and windows;
command line interface:
-commands are given to computer with keyboard
-difficult to use
-disk operating system (DOS) - single user & single task OS
-UNIX - multi-user, developed for use on large computer systems
menu driven interface:
-the user reads the options and makes his choices
-easy to use
-also used in some application programs
-novell's netware and proDOS
graphical user interface:
-uses windows, icons, menus and pointer
-user has to select icons or make choices using a pointing device
-easiest to use
-takes up alot of memory
-needs faster computer
-macintosh OS - developed by apple incorporation for macintosh computers
-linux OS - free, open-source, faster but difficult to use than mac OS and windows OS
-windows OS - most popular
Im sorry mujh mein himmat nhin bachi ch2 saara aesa hi hoga book dekhlo pls
2.2.1 classify OS into single user and multiuser OS;
Single-user operating system:
Operating system that is used by a single user at a time is known as single-user operating
system.
● It allows a single user to log in and use the computer at a time. It is easy to use.
● Resources of the computer, such as CPU, memory and I/O devices are not shared with
other computers.
● It is used on microcomputers.
● User can open many programs at the same time and switch among them as required.
● It requires less memory and costs less.
● Some examples of single user operating systems are DOS, windows 95, windows XP,
windows 7, etc.
Multi-user operating system:
Operating system that allows many users to use a computer at the same time is known as
multi-user operating system.
 ● It allows many users to log in to a single big computer and run different programs at the
same time.
● It shares the resources of the computer with other users over the network
● It is used on minicomputers and mainframes.
● Users can communicate with each other and share files.
● A person known as administrator is responsible for assigning and managing user names
and passwords.
● It requires a powerful CPU, large memory and large hard drives.
● It supports multiprogramming and time-sharing
● Windows NT, UNIX and linux are popular multi-user operating systems.
2.2.2 differentiate among the following types of OS;
a. batch processing system
b. time sharing system
c. real time system
Batch processing system:
- jobs are grouped in batches and the computer executes them one by one.
- suitable for tasks where large amount of data has to be collected and processed on daily basis
timesharing system:
- multiple users can run different programs on a large-scale computer.
- share the computer's time
- in a timesharing system the CPU is switched rapidly between the programs so that all user
programs are executed simultaneously
- the OS used in minicomputers and mainframes support time sharing.
real time system:
- must process information and produce a response within a specified time.
- developed for special applications
- used to control industrial processes
4.1.1 Define data communication;
Data communication refers to the exchange of data between two or more devices using a
communication channel. It involves the transmission of digital or analog signals over a
communication medium such as cables, wireless networks, or satellite links. Data
communication enables devices to communicate and share information with each other.
4.1.2 Differentiate between data and data transmission;
Data refers to the raw facts, figures, and symbols that are processed by computers to produce
meaningful information. On the other hand, data transmission refers to the process of sending
data from one device to another over a communication channel.
In other words, data transmission is the movement of data from one place to another, while
data refers to the actual content being transmitted. Data can be transmitted in various forms
such as text, images, audio, or video. Data transmission involves encoding data into a format
that can be transmitted over a communication channel, transmitting it through the channel,
and then decoding it at the receiving end to restore it to its original format.
Features Data Data Transmission
Data refers to any Data Transmission refers
information that is to the process of
collected, stored, or transferring data from
Definition processed for later use one location to another
Data Transmission
Data can be in various involves the movement
forms such as text, of data over a
numbers, images, communication channel
Nature videos, and sounds or network
Data can be stored on
physical or electronic Data Transmission
media such as hard occurs through various
drives, solid-state physical media such as
drives, or cloud cables, radio waves, or
Medium storage satellite signals
The purpose of The objective of data
collecting and storing transmission is to send
data is to make it data from one location
available for later use, to another in a reliable
Objective analysis, or processing and efficient manner
Features Data Data Transmission
Data storage capacity Data transmission
is limited by physical capacity is limited by
storage space or the bandwidth of the
technological communication channel
Capacity limitations or network
Data can be protected
through various Data Transmission can
security measures be secured through
such as encryption, various protocols such
authentication, and as SSL, VPN, and
Security access control firewalls
Examples of data
Examples of data transmission include
include customer sending emails,
information, financial streaming videos,
records, sales data, downloading files, and
Examples and inventory data making voice calls

4.1.3 Differentiate between analog and digital signals;

Features Analog Signal Digital Signal
An analog signal is a A digital signal is a discrete
continuous wave that wave that consists of a
varies in amplitude and sequence of on/off or
Definition frequency over time high/low states
Analog signals represent Digital signals represent
information through a information through a
Representation continuous range of values series of discrete values
Digital signals are less
Analog signals are susceptible to noise and
susceptible to noise and distortion, which means
distortion, which can affect they can be more reliable
Nature their quality and accurate
Analog signals are Digital signals are
Transmission transmitted over analog transmitted over digital
Features Analog Signal Digital Signal
channels such as copper channels such as fiber
wires, radio waves, or optic cables, digital
optical fibers satellite links, or Wi-Fi
Analog signals require
more bandwidth to Digital signals require less
transmit than digital signals bandwidth to transmit
because they have a higher because they have a lower
Bandwidth frequency range frequency range
Analog signals are Digital signals are
processed using analog processed using digital
circuits that can amplify, circuits that can encode,
filter, or modulate the decode, or compress the
Processing signal signal
Analog signals are stored Digital signals are stored
on analog media such as on digital media such as
vinyl records, cassette hard drives, flash drives, or
Storage tapes, or VHS tapes cloud storage
Examples of digital signals
Examples of analog signals include binary code,
include sound waves, radio computer data, and digital
Examples signals, and light waves audio and video signals

Analog signals are continuous waves that vary in amplitude, frequency, or phase, while digital
signals are discrete signals represented by binary digits (bits) that have only two possible
values, 0 and 1. Analog signals are used to represent analog data such as sound, images, or
video, while digital signals are used to represent digital data such as text, numbers, or
computer code.
4.1.4 identify the components of a communication system, i.e. sender, receiver, message,
protocol and transmission medium;
The components of a communication system include:
● Sender: The device or system that initiates the communication and sends the message.
● Receiver: The device or system that receives the message sent by the sender.
● Message: The information or data that is being communicated.
● Protocol: The set of rules and procedures that govern the communication between the
sender and the receiver.
 ● Transmission Medium: The physical pathway through which the message is transmitted,
such as cables, fiber optics, or wireless signals.
4.1.5 describe the following characteristics of a good communication system:
Characteristics of a good communication system include:
a. Delivery: The message should be delivered to the intended receiver accurately and timely.
The system must deliver data to the exact destination. No other receiver should receive the
data.
b. Accuracy: The message should be transmitted without any errors or distortion and should
be received accurately. The data communication system must deliver data to the receiver
without being altered or damaged. The receiver should receive the exact same data which was
sent by the sender. The protocol might require to alter the sent data to protect and optimize
the process.
c. Timeliness: The message should be transmitted and received in a timely manner, without
any significant delay. Timeliness refers to the time expectation for accessibility and availability
of information. Timeliness can be measured as the time between when information is
expected and when it is readily available for use.
4.1.6 differentiate between the synchronous and asynchronous data transmission methods;
Feature Synchronous Transmission Asynchronous Transmission
Does not require a common clock
Requires a common clock signal signal. The timing of the
between the sender and receiver transmission is determined by start
Timing to synchronize the transmission. and stop bits.
Data is transmitted in a Data is transmitted in packets with
continuous stream, with no gaps start and stop bits, and a gap
Data Transfer between the bits. between each packet.
Provides more reliable error Provides less reliable error checking
checking and correction due to and correction due to the
Error Checking the continuous flow of data. packetized transmission.
Transmission Offers high-speed transmission Offers relatively slower
Rate rates. transmission rates.
Synchronous transmission is used Asynchronous transmission is used
in applications like audio and in applications like text messaging
video streaming, where timing is and email, where timing is not
Examples critical. critical.
4.2.1 compare guided (wired) and unguided (wireless) media with examples, i.e. twisted pair
cable, coaxial cable, optic fibre cable, radio waves, microwave, infra-red, Bluetooth and
satellite;
Guided (Wired) Media: Guided media refers to the transmission of data through physical cables
or wires. These cables guide the signal through a specific path and have higher bandwidth and
transmission rates than unguided media. The commonly used guided media are:

1. Twisted Pair Cable: It is the most common type of guided media that uses copper wires
twisted together to reduce signal interference. It is used for telephone lines, LAN
connections, and Ethernet connections.

2. Coaxial Cable: It is a copper-based cable that has a central conductor surrounded by an

insulating layer and a braided shield. It is used in cable TV connections, broadband
internet, and CCTV applications.

3. Optic Fiber Cable: It is a high-speed cable that transmits data through light waves, which
offers higher bandwidth and faster transmission rates than copper cables. It is used in
high-speed internet connections, long-distance data transmission, and cable TV
connections.

Unguided (Wireless) Media: Unguided media refers to the transmission of data through the air
without the use of physical cables or wires. These signals are not restricted to a specific path,
and hence they are also called wireless media. The commonly used unguided media are:

1. Radio Waves: It is a wireless transmission medium that uses electromagnetic waves to

carry data between devices. It is used for AM/FM radio broadcasts, television
broadcasting, and satellite communications.

2. Microwave: It is a high-frequency electromagnetic wave that is used for long-distance

communication, cellular communication, and satellite communication.

3. Infrared: It is a short-range wireless transmission medium that uses light waves to

transmit data between devices. It is used in remote control devices, wireless
headphones, and proximity sensors.

4. Bluetooth: It is a short-range wireless transmission medium that uses radio waves to

connect devices within a range of 10 meters. It is used in wireless speakers, mobile
phones, and wireless headphones.

5. Satellite: It is a wireless transmission medium that uses orbiting satellites to transmit

data between devices. It is used for global communication, TV broadcasting, and GPS
navigation.

GUIDED MEDIA
 CO-AXIAL CABLE TWISTED PAIR CABLE OPTICAL FIBER
SIGNAL ATTENUATION Attenuation is low as compared to Attenuation is very Attenuation is very
twisted pair high low

DATA RATE Moderately high data rate. Twisted pair cable Very high data rate.
supports low data
rate.

INSTALLATION Installation and implementation is Easy to install, Installation and

relatively difficult maintain and operate implementation is
quite difficult

COST More Expensive than twisted Twisted pair cables Expensive than
are comparatively coaxial cable and
inexpensive and easily twisted cable
affordable

BANDWIDTH Moderately high bandwidth Low bandwidth Very high bandwidth

capacity

ELECTROMAGNETIC EMI is reduced to shielding. EMI can take place. EMI is not present
INTERFERENCE(EMI)

EXTERNAL MAGNETIC FIELD External magnetic field is less affected . Affected due to External magnetic
external magnetic field is not affected.
field.

SECURITY Low Low High(It is more

(Signal transmission security is not to (Signal transmission reliable for data
guarantee) security is not to security. Data cannot
guarantee) be tapped or stolen )

DISTANCE Long distance Short distance Very long distance

In order to use
twisted pair cables for
long distance, needs a
signal regenerating
device called
repeater

WEIGHT The coax cables are heavier in weight The cables tend to be Tend to be
quite heavy lightweight in nature

NOISE Relatively good for noise rejection Not suitable for noise Topnotch when it
rejection comes to noise
rejection

NOISE IMMUNITY Co-axial cable has higher noise Twisted pair cable has Optical fiber cable has
(Internal ckt noise) immunity. low noise immunity. highest noise
immunity.
USES Coaxial cables are used in feed lines Used in the telephone Used to support
connecting radio transmitters and network, data long-distance
receivers with their antennas, computer network, and cable connections between
network (Internet) connections, digital shielding countries and cities.
audio (S/PDIF) and distributing cable They are also used in
television signals. They are also used in data centers where
for high-definition media interface large volume of data
connections. needs to be
transmitted.

UNGUIDED MEDIA
MICROWAVE RADIO WAVES INFRARED BLUETOOTH SATELLITE
Microwaves are a type Radio waves are the It uses infrared light Bluetooth uses radio
Communication
of electromagnetic electromagnetic to transmit signals. waves to connect
satellite is space
waves as are radio waves LED is used to portable electronic
station. It receives
waves that are that are transmitted transmit signals and devices for microwave signals from
propagates in straight in all the directions light-receivers communication. earth station. It
line. of free space(air) (photodiodes) to It creates personal
amplifies the signals
receive signals area network (PAN)
and retransmits them
back to earth.
Unidirectional Omnidirectional Unidirectional Omnidirectional Unidirectional
LINE OF SIGHT NO LINE OF SIGHT LINE OF SIGHT NO LINE OF SIGHT LINE OF SIGHT
Cannot penetrate solid Can penetrate Cannot penetrate Can pass through Cannot penetrate solid
objects and walls through solid walls or other objects solid objects objects and walls
objects and walls
Frequency range: 1 GHz Frequency range: 3 Frequency range: 300 Frequency: Use different band for
to 300 GHz. KHz to 1GHz. GHz to 400 THz. 2.402 GHz to 2.48 different purpose
GHz
Medium security Poor security. High security. Good security Medium security
long range long range It is short range It is short range Very long-range
communication communication communication up to communication up wireless
5 meters (not to 10-30 meters (not communication
constant) constant)
Attenuation is variable. Attenuation is high Attenuation is low. Attenuation is very weather attenuation
low
Cost is high Cost is moderate. Cost is very less. Inexpensive Very high cost
microwave oven, AM and FM radio, thermography, laptops, printers, weather forecasting,
satellite television, infrared viewer, pda, head phones, radio/tv signal
communication, radar, marintime radio, infrared lamp, gaming console, broadcasting, mobile
cordless phones, remote control, cellular phones, communication,
wlan, space and paging. auto-focus camera; internet, global
fire detectors positioning system
communication,
night vision systems,
cellular phones,
intrusion detection
television networks, systems, motion
aircraft navigation detectors
4.2.2 differentiate among the following transmission impairments in communication media:
a. attenuation
b. amplification
c. distortion
d. crosstalk;
Transmission
Impairment Definition Cause Effect
Weaker signal at the
Loss of signal strength receiver end, leading to
as it travels through the errors, slow
communication Distance, resistance, transmission rates, and
Attenuation medium. and interference. loss of data.
Stronger signal at the
receiver end, improving
transmission rates and
reducing errors.
Increase in signal Long distance, low However, it can also
strength to overcome signal strength, and amplify noise and
Amplification the attenuation. weak signals. distortion in the signal.
Alteration of the signal
shape or quality due to
interference, noise, or Interference, noise,
non-linearities in the temperature, and Signal errors, incorrect
communication manufacturing decoding, and loss of
Distortion medium. defects. data.
Interference caused by
signals from adjacent Proximity of
communication communication
channels, leading to channels, inadequate
signal bleeding and loss shielding, and high Signal distortion, errors,
Crosstalk of data. signal strength. and data loss.

4.3.1 identify the purpose of the following communication devices:

a. dialup modem
b. network interface card (NIC)
c. router
d. switch
e. hub;
a) Dial-up modem: use standard telephone lines to transmit and receive information. A
dialup modem can be internal or external. It is important to remember that telephone
lines carry only analog signals, whereas data packets sent by the computer are in digital
form. In order to send these packets across a telephone line, modem converts digital
signals into analog.
b) Network interface card: network cards also known as network interface cards (NICs) are
hardware devices that connect a computer with the network. They are installed on the
motherboard. They are responsible for establishing a physical connection between the
network and the computer. Computer data is translated into electrical signals and sent
to the network via network interface cards. Modern motherboards have built-in NICs.
c) Router: a router is a device that connects two or more networks. Routers are a
combination of hardware and software. The main function of a router is to determine
the optimal data and transfer the information through that path, also known as network
traffic controller.
d) Switch: a switch or network switch is a networking device that connects computers and
other devices like printers, scanners and cameras on a network. Data cables from all
computers and other devices of network are plugged into the switch to enable
communication between them.
e) Hub: A hub is a communication device that connects multiple devices in a network and
allows them to communicate with each other. It receives data from one device and
broadcasts it to all other devices in the network. It does not manage the flow of network
traffic like a switch does.
4.4.1 define the terms data rate, baud rate, bandwidth and signal-to-noise ratio;
● Data rate/bit rate: data rate is the rate at which data is transferred. It is normally
measured in bits per second. Bit is the actual binary digit which is the basic unit of data
transmission.
● Baud rate: baud rate is the number of signals transmitted per second and one signal
represent one or more bits.
● Signal-to-noise ratio, SNR, S/N: signal to noise ratio is a measured used in engineering
that compares the level of a desired signal and the level of background noise. It is
defined as the ratio of signal power to the noise power, often expressed in decibels.
● Bandwidth: bandwidth determines the maximum data rate that can be transmitted over
a communication channel. The wider the bandwidth, the higher the maximum data rate
 that can be achieved. Conversely, a narrower bandwidth can limit the maximum data
rate that can be transmitted.
4.4.2 convert baud rate to data rate and vice versa;
𝑏𝑖𝑡 𝑟𝑎𝑡𝑒 = 𝑏𝑎𝑢𝑑 𝑟𝑎𝑡𝑒 ×𝑡ℎ𝑒 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑏𝑖𝑡𝑠 𝑝𝑒𝑟 𝑠𝑖𝑔𝑛𝑎𝑙 𝑢𝑛𝑖𝑡
𝑏𝑖𝑡𝑟𝑎𝑡𝑒
𝑏𝑎𝑢𝑑 𝑟𝑎𝑡𝑒 = 𝑡ℎ𝑒 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑏𝑖𝑡𝑠 𝑝𝑒𝑟 𝑠𝑖𝑔𝑛𝑎𝑙 𝑢𝑛𝑖𝑡
4.4.3 convert one unit of data rate into other such as bit per second (bps), kilobit per second
(kbps), kilobyte per second (kBps), kibibyte per second (KiBps), Megabit per second (Mbs),
Megabyte per second (MBps), Mebibyte per second (MiBps) Gigabit per second (Gbps),
Gigabyte per second (GBps) and Gibibyte per second (GiBps);
1. 1 bit per second (bps) = 0.001 kilobits per second (kbps)
2. 1 kilobit per second (kbps) = 1000 bits per second (bps)
3. 1 kilobyte per second (kBps) = 8 kilobits per second (kbps)
4. 1 kibibyte per second (KiBps) = 1024 bytes per second
5. 1 Megabit per second (Mbps) = 1000 kilobits per second (kbps)
6. 1 Megabyte per second (MBps) = 8 Megabits per second (Mbps)
7. 1 Mebibyte per second (MiBps) = 8.39 Megabytes per second (MBps)
8. 1 Gigabit per second (Gbps) = 1000 Megabits per second (Mbps)
9. 1 Gigabyte per second (GBps) = 8 Gigabits per second (Gbps)
10.1 Gibibyte per second (GiBps) = 8.59 Gigabytes per second (GBps)
Note: The conversion of data rate units is based on the decimal and binary prefixes. Decimal
prefixes (kilo, mega, giga) use multiples of 1000, while binary prefixes (kibi, mebi, gibi) use
multiples of 1024.

5.1.1 define a computer network;

A computer network is a system of interconnected devices that allow users to share resources
and communicate with each other, making it possible to collaborate and work together,
regardless of their physical location.
A computer network is a set of computers that are connected together so that they can share
information and resources. Computers on a network are called nodes. The connection
between computers can be done via cabling, most commonly the Ethernet cable, or fiber optic
cable. Connections can also be wireless, like Wi-fi (Wireless Fidelity) technology. Sharing
resources means to share printer, access to the internet.
5.1.2 describe the uses of networks;
 1. Hardware sharing: Networks enable multiple users to share hardware resources such as
printers, scanners, and storage devices. This reduces the need for each user to have their
own separate hardware, which can be expensive and inefficient.
2. Software sharing: Networks allow multiple users to share software applications and
licenses, which can reduce costs and increase efficiency. This enables users to access
software programs that are installed on a central server, rather than having to install the
software on each individual computer.
3. File sharing: Networks allow users to share files and documents with each other, making
it easier to collaborate on projects and work together. This can be particularly useful in
businesses and organizations where multiple users need access to the same files and
information.
4. Internet sharing: Networks allow multiple users to access the internet simultaneously,
sharing a single internet connection. This can be particularly useful in homes, small
businesses, and other environments where multiple users need internet access but do
not want to pay for separate connections.
5.1.3 describe advantages of computer networks;
1. Resource sharing: Networks allow users to share resources such as printers, scanners,
storage devices, and software applications. This reduces the need for each user to have
their own separate resources, which can be expensive and inefficient.
2. Improved communication: Networks facilitate communication between users, enabling
them to share information and collaborate on projects in real-time, regardless of their
location.
3. Increased productivity: Networks enable users to access resources and information
quickly and efficiently, which can improve productivity and reduce the time it takes to
complete tasks.
4. Centralized management: Networks enable centralized management of resources,
including hardware, software, and data. This makes it easier for administrators to
manage and maintain the network, ensuring that all devices are up-to-date and secure.
5. Cost savings: Networks can be more cost-effective than individual devices, as they
enable resource sharing and reduce the need for duplicate hardware and software.
6. Scalability: Networks can be easily expanded as an organization grows, by adding
additional devices and resources to the network.
5.1.4 differentiate among three data transmission modes simplex, half-duplex and fullduplex
with examples;
Data
Transmission
Mode Definition Examples
In simplex mode, data can only be
transmitted in one direction. The receiver
can only receive data and cannot send any Radio and television
Simplex data back. broadcasting.
In half-duplex mode, data can be
transmitted in both directions, but not at
the same time. A device can only either Walkie-talkies and
Half-duplex send or receive data at a given time. two-way radios.
In full-duplex mode, data can be transmitted
in both directions simultaneously. Both Telephone
devices can send and receive data at the conversations and
Full-duplex same time. video conferencing.
5.1.5 explain the following types of network architecture, i.e. client/ server network,
peer-to-peer network, point-to-point network;
Client/server network:
● Client/Server network is a network model designed for the end users called clients, to
access the resources such as songs, video, etc. from a central computer known as Server.
● The central controller is known as a server while all other computers in the network are
called clients.
● A server performs all the major operations such as security and network management.
● A server is responsible for managing all the resources such as files, directories, printer,
etc.
● All the clients communicate with each other through a server. For example, if client1
wants to send some data to client 2, then it first sends the request to the server for the
permission. The server sends the response to the client 1 to initiate its communication
with the client 2.
Advantages Of Client/Server network:
● A Client/Server network contains the centralized system. Therefore we can back up the
data easily.
● A Client/Server network has a dedicated server that improves the overall performance of
the whole system.
● Security is better in Client/Server network as a single server administers the shared
resources.
 ● It also increases the speed of the sharing resources.
Disadvantages Of Client/Server network:
● Client/Server network is expensive as it requires the server with large memory.
● A server has a Network Operating System(NOS) to provide the resources to the clients,
but the cost of NOS is very high.
● It requires a dedicated network administrator to manage all the resources.
Peer-to-peer network:
● Peer-To-Peer network is a network in which all the computers are linked together with
equal privilege and responsibilities for processing the data.
● Peer-To-Peer network is useful for small environments, usually up to 10 computers.
● Peer-To-Peer network has no dedicated server.
● Special permissions are assigned to each computer for sharing the resources, but this
can lead to a problem if the computer with the resource is down.
Advantages Of Peer-To-Peer Network:
● It is less costly as it does not contain any dedicated server.
● If one computer stops working but, other computers will not stop working.
● It is easy to set up and maintain as each computer manages itself.
Disadvantages Of Peer-To-Peer Network:
● In the case of Peer-To-Peer network, it does not contain the centralized system .
Therefore, it cannot back up the data as the data is different in different locations.
● It has a security issue as the device is managed itself
Point-to-point networks:
● It is a type of network in which a message is sent from one computer to another via
other computers in the network. Large networks such as wide area networks that
connect cities and countries are organized in such a way.
● Generally used for long distance networks
5.2.1 differentiate among the following types of networks:
a. local area network (LAN)
b. metropolitan area network (MAN)
c. wide area network (WAN)
d. personal area network (PAN)
e. Bluetooth network
f. internet;
Network Type Definition Coverage Examples
A LAN is a network that
connects devices within a small Typically covers Home networks,
Local Area geographical area, such as a a few hundred office networks,
Network (LAN) home, office, or building. meters or less. school networks.
A MAN is a network that
Metropolitan connects devices within a larger Typically covers Cable TV networks,
Area Network geographical area, such as a city several public utility
(MAN) or town. kilometers. networks.
A WAN is a network that
connects devices across a large
geographical area, such as a Can cover Internet, private
Wide Area country, continent, or even the thousands of leased lines,
Network (WAN) world. kilometers. satellite networks.
A PAN is a network that
connects devices within a Wireless
person's immediate vicinity, Typically covers headphones,
Personal Area typically within a range of 10 less than 10 wireless keyboards,
Network (PAN) meters or less. meters. smartwatches.
A Bluetooth network is a type of Wireless
PAN that uses Bluetooth Typically covers headphones,
Bluetooth technology to connect devices less than 10 smartphones, smart
Network wirelessly over short distances. meters. speakers.
The internet is a global network
of interconnected devices and
networks that enables Websites, email,
communication and information Global social media, online
Internet sharing across the world. coverage. services.
5.2.2 define a network topology;
The physical arrangement of network nodes is called network topology. A node represents a
computer or a network device. It describes how different devices are connected to each other
and how data flows through the network. Topology can be classified into several types,
including bus, ring, star, mesh, tree, and hybrid.
5.2.3 explain the following network topologies with the help of diagrams, i.e. bus topology,
ring topology, star topology and mesh topology;
Bus topology: In bus topology computers and other devices are connected with single cable.
The central cable is the backbone of the network and every device communicates with the
other device through this bus. The advantages of bus topology are simplicity, low cost and easy
expansion of the network. The disadvantage of the bus topology is that a breakdown in the bus
cable brings the entire network down. A computer sends a message on the bus. The computer
to whom the message is sent receives it while others ignore it. At each end of bus a device
called terminator is attached so that the signals do not bounce back on the bus causing errors.
Ring topology: In ring topology, computers are connected in a ring or circle shape. The signal
travels around the loop in one direction and passes through each computer. The recipient of
the message receives the message while another computer acts like a repeater to send it to
the next computer. The failure of a link or a computer can make the entire network
non-functional.
Star topology: In a star topology, all the computers are connected to a central device called
hub or switch. To communicate with any computer, the sender must send information to the
hub. Then the hub transmits that information to the destination. The advantages of star
topology are easy to set up and easy expansion of the network. Another feature of star
topology is that if one link to the hub breaks, only the station using that link is affected not the
whole network.
Mesh topology: In mesh network topology, all the network nodes are connected to all the
other nodes. Its not common since its expensive and hard to implement or add a node. It is the
most reliable since alternative paths are available in case a path is broken from source to
destination.
5.3.1 describe the following types of technologies which use the telephone networks for
data communications:
a. dial-up
b. digital subscriber line (DSL)
c. integrated services digital network (ISDN)
d. code-division multiple access (CDMA);
a. Dial-up: Dial up line uses standard telephone lines for internet connection. It requires a
dial-up modem that provides a maximum internet connection speed of 56Kbps. The
main advantage of using dial-up line is that it uses complex network of telephone lines
that allows data to be transmitted to almost any location in the world. It is becoming
outdated due to very slow internet connection.
● Maximum speed is 56kbps.
● Easily available anywhere, no extra lines required.
● Cheaper than other internet services.
 ● Internet connection is not permanently available
● Voice communication is not possible while using internet
b. Digital subscriber line (DSL): DSL stands for digital subscriber line. Like dial-up modem
DSL modem also uses telephone lines to transfer digital signals. DSL modem has a
built-in network switch which enables use of twisted pair wires to deliver data and voice
at high speed as compare to dial-up modem. Some DSL modems also have wireless
communication functionality.
● Typical speed is 256 Kbps or above.
● DSL connection is always available
● Telephonic conversation and internet access are available simultaneously.
● Costly than other types of internet services
● Various monthly rates are charged depending on the speed.
● Connection is available as soon as computer and DSL modem are turned on.
c. Integrated services digital network (ISDN): integrated services digital network is a digital
phone connection that can transmit data, voice and video over a normal telephone line
at the same time which was not done before. It is faster and expensive technology. Since
ISDN work on digital transmission it converts analog voice to digital signals before
transmission.
● Maximum communication speed is 128 Kbps.
● Costs more than dial-up service.
● Can simultaneously transmit both voice and data.
● Allows multiple devices to share a single line.
d. Code-division multiple access (CDMA): CDMA is a wireless communication technology
that uses cellular networks to transmit data. It works by dividing the available bandwidth
into small channels and assigning each channel to multiple users. This allows multiple
users to share the same frequency range and transmit data simultaneously. CDMA is
commonly used for mobile phone networks and wireless data communication.
● it is a wireless cellular communication technology
● Transmission speed can be up to a several Mbps.
● Can provide service to many people at the same time.
● Provides improved voice quality.
5.3.2 compare the data communication lines mentioned in SLO 5.3.1 on the basis of:
a. transfer rates
b. costs per month
c. advantages
d. disadvantages
Technology Transfer Costs per Advantages Disadvantages
Rates Month

Dial-up Up to 56 Low Widely available, Low Slow speeds, Disrupts

Kbps cost hardware phone lines, Limited
functionality

DSL Up to 100 Low to Faster speeds than Distance limitations,

Mbps Medium dial-up, Always-on Limited availability in rural
connection, Affordable areas

ISDN Up to 128 Medium Fast speeds, Supports Limited availability, Higher

Kbps to High voice and data, costs than DSL
Dedicated line

CDMA Up to 3.1 High Widely available, Mobile Limited bandwidth, Limited

Mbps connectivity range, Susceptible to
interference
6.1.1 differentiate among the following terms:
a. World Wide Web (WWW)
b. web page
c. web site
d. web browser
e. web server
f. Uniform Resource Locator (URL)
g. search engine
h. home page
i. web hosting;
a. World wide web (WWW): The world wide web (www) is commonly known as the web. The
web is a collection of computers connected through a network to provide publicly accessible
information. Simply put, it is the main application of internet for accessing and sharing
information. It allows people all over the world to share knowledge and ideas.
b. Web page: A web page is a document commonly written in HTML that is accessible through
internet by using internet browser.
c. Web site: A website is a collection of related web pages hosted on a web server. It accessible
through an internet address known as Uniform resource locator (URL).
d. Web browser: a web browser is a software application for accessing websites on the world
wide web. Web browsers allow users to open multiple websites at the same time, either in
different browser windows or in different tabs of the same window. All the browsers have GUI.
e. Web server: A web server is the computer that is responsible for serving a website and all of
its content including text and media to a user.
f. Uniform Resource Locator (URL): It is the address of a resource on the internet. It includes
the following 3 components:
● Protocol: the first part, http:// is known as protocol. It tells the server what type of file is
being requested.
● Resource name: it is the address of a specific computer where the website is located. It
consists of three parts:
1. Domain name: this the name of the website. This the name that the browser uses
to check with the web server whether this site exists or not.
2. Top-level domain: the .com is referred to as the top level domain (TLD). This is the
name the browser will use to resolve the location of the requested site. Most
common TLDs are .com, .org, .net etc. Some sites have country code top-level
domain (ccTLD). They are specific to each country.
● File path: it links to a specific page or resource in the website.
g. Search engine: A search engine is a website or a tool that helps you find information on the
internet. Examples of search engines include Google, Bing, and Yahoo. You can type in
keywords or phrases, and the search engine will show you a list of web pages related to your
search.
h. Home page: The home page is the main or starting page of a website. It's the first page that
you see when you visit a website. It usually provides an overview of what the website is about
and includes links to other pages within the website.
i. Web hosting: Web hosting refers to the service of storing and making websites available on
the internet. Web hosting companies provide servers where website files are stored and
ensure that the websites are accessible to users when they visit the web address.
6.2.1 define Hypertext Markup Language (HTML);
a. Hypertext Markup Language (HTML): HTML is a programming language used to create and
structure web pages. It stands for Hypertext Markup Language. It uses special codes called
"tags" to define different elements of a webpage, such as headings, paragraphs, images, links,
and more. HTML provides instructions to web browsers on how to display and format the
content of a webpage.
6.2.2 describe the steps involved to:
a. create and save an HTML file
b. display a webpage;
a. Steps to create and save an HTML file:

1. Open a text editor: Start by opening a simple text editor like Notepad (Windows) or
TextEdit (Mac).

2. Write HTML code: In the text editor, type or copy and paste your HTML code to create
the structure and content of your webpage. You can include headings, paragraphs,
images, links, and other HTML tags to customize your page.

3. Save the file: Once you have written your HTML code, go to the "File" menu and choose
"Save As." Give your file a name, and make sure to add the ".html" extension at the end
of the filename. This extension tells the computer that the file is an HTML file.

b. Steps to display a webpage:

1. Open a web browser: Launch a web browser like Google Chrome, Mozilla Firefox, or
Safari.
 2. Open the HTML file: In the web browser, go to the "File" menu and choose "Open File"
or "Open." Locate the HTML file you created and saved earlier, then select it and click
"Open."

3. View the webpage: The web browser will display the contents of your HTML file as a
webpage. You'll be able to see the text, images, links, and other elements you included
in your HTML code.

6.3.1 write HTML code to:

a. specify a page title
b. create a paragraph
c. insert line breaks
d. insert spaces
e. add headings/ sub-headings;
a. Specify a page title: To specify a page title, you can use the <title> tag within the <head>
section of your HTML document. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<!-- Your webpage content goes here -->
</body>
</html>

b. Create a paragraph: To create a paragraph, you can use the <p> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<p>This is a paragraph.</p>
</body>
</html>
c. Insert line breaks: To insert line breaks, you can use the <br> tag. Here's an example:

<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
This is the first line.<br>
This is the second line.
</body>
</html>

d. Insert spaces: To insert spaces, you can use the &nbsp; entity. Here's an example:

<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
This is some text with&nbsp;&nbsp;&nbsp;spaces between&nbsp;words.
</body>
</html>

e. Add headings/sub-headings: To add headings or sub-headings, you can use the <h1> to <h6>
tags, with <h1> being the largest heading and <h6> being the smallest. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<h1>This is a Heading 1</h1>
<h2>This is a Heading 2</h2>
<h3>This is a Heading 3</h3>
 <h4>This is a Heading 4</h4>
<h5>This is a Heading 5</h5>
<h6>This is a Heading 6</h6>
</body>
</html>

6.3.2 apply appropriate text formatting tags, i.e. bold, underline, italic, strikethrough,
superscript, subscript, center, font size, font color and font face;

a. Bold: To make text bold, you can use the <b> or <strong> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<p>This is <b>bold</b> text.</p>
</body>
</html>

b. Underline: To underline text, you can use the <u> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<p>This is <u>underlined</u> text.</p>
</body>
</html>

c. Italic: To make text italic, you can use the <i> or <em> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<p>This is <i>italic</i> text.</p>
</body>
</html>

d. Strikethrough: To add a strikethrough to text, you can use the <s> or <del> tag. Here's an
example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<p>This is <s>strikethrough</s> text.</p>
</body>
</html>

e. Superscript: To make text appear as superscript, you can use the <sup> tag. Here's an
example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<p>This is ^superscript text.</p>
</body>
</html>

f. Subscript: To make text appear as subscript, you can use the <sub> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<p>This is _subscript text.</p>
</body>
</html>

g. Center: To center-align text, you can use the <center> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<center>
<h1>This is centered text</h1>
<p>This is some centered paragraph.</p>
</center>
</body>
</html>

h. Font size: To set the font size, you can use the <font> tag with the size attribute. Here's an
example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<p>This is <font size="5">larger</font> text.</p>
</body>
</html>

i. Font color: To change the font color, you can use the <font> tag with the color attribute.
Here's an example:
<!DOCTYPE html>
<html>
<head>
 <title>My Page Title</title>
</head>
<body>
<p>This is <font color="red">red</font> text.</p>
</body>
</html>

j. Font face: To change the font face, you can use the <font> tag with the face attribute. Here's
an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<p>This is <font face="Arial">Arial</font> text.</p>
</body>
</html>

6.4.1 write HTML code to create:

a. ordered list
b. unordered list
c. definition list;

a. Ordered list: To create an ordered list (a numbered list), you can use the <ol> tag, and each
list item is represented by the <li> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<ol>
<li>First item</li>
<li>Second item</li>
<li>Third item</li>
 </ol>
</body>
</html>

b. Unordered list: To create an unordered list (a bulleted list), you can use the <ul> tag, and
each list item is represented by the <li> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<ul>
<li>First item</li>
<li>Second item</li>
<li>Third item</li>
</ul>
</body>
</html>

c. Definition list: To create a definition list, where each term is followed by its definition, you
can use the <dl> tag. Within the <dl> tag, use the <dt> tag for terms (definitions), and the <dd>
tag for their respective definitions (descriptions). Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<dl>
<dt>Term 1</dt>
<dd>Definition 1</dd>
<dt>Term 2</dt>
<dd>Definition 2</dd>
<dt>Term 3</dt>
<dd>Definition 3</dd>
 </dl>
</body>
</html>

6.5.1 write HTML code to:

a. insert an image
b. apply border to an image;

a. Insert an image: To insert an image, you can use the <img> tag and specify the image source
using the src attribute. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<img src="image.jpg" alt="Description of the image">
</body>
</html>

b. Apply border to an image: To apply a border to an image, you can use the style attribute and
specify CSS properties within the <img> tag. Here's an example to apply a black border of 2
pixels to the image:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<img src="image.jpg" alt="Description of the image" border="2">
</body>
</html>

6.5.2 write HTML code to select:

a. width of an image
b. height of an image
c. an alternate text for an image;

a. Select width of an image: To specify the width of an image, you can use the width attribute
within the <img> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<img src="image.jpg" alt="Description of the image" width="300">
</body>
</html>

b. Select height of an image: To specify the height of an image, you can use the height attribute
within the <img> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<img src="image.jpg" alt="Description of the image" height="200">
</body>
</html>

c. Select alternate text for an image: To provide alternate text (also known as "alt text") for an
image, you can use the alt attribute within the <img> tag. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<img src="image.jpg" alt="This is the alternate text">
</body>
</html>

6.5.3 write HTML code to:

a. apply background colour to a web page
b. apply foreground colour to a web page
c. assign a background image to the web page;

a. apply background colour to a web page

<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body bgcolor=red>
<!-- Your webpage content goes here -->
</body>
</html>

b. apply foreground colour to a web page

<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body text=yellow>
<!-- Your webpage content goes here -->
</body>
</html>

c. assign a background image to the web page;

<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body background=computer.jpg>
 <!-- Your webpage content goes here -->
</body>
</html>

6.6.1 write HTML code to create a hyperlink to a web page;

a. Create a hyperlink to a web page: To create a hyperlink to a web page, you can use the <a>
tag with the href attribute. Here's an example:
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<a href="https://www.example.com">Visit Example.com</a>
</body>
</html>

6.6.2 create an ‘anchor’ in the context of hyperlinks;

<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<h2><a name="section1"></a>Section 1</h2>
<!-- Your webpage content goes here -->
</body>
</html>

6.6.3 create an anchor to hyperlink within a web page;

<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
 <a href="#section1">Go to Section 1</a>
<!-- Your webpage content goes here -->
<h2><a name="section1"></a>Section 1</h2>
<!-- More content -->
</body>
</html>

6.6.4 create a graphical hyperlink;

<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<a href="https://www.example.com">
<img src="image.jpg" alt="Description of the image">
</a>
</body>
</html>

6.7.1 write HTML code to create a table in the webpage with the following table attributes:
a. table border
b. border colour
c. background colour
d. table width
e. table height
f. table row
g. standard cell
h. header cell;
<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<body>
<table border="1" bordercolor="black" bgcolor="lightgray" width="400" height="300">
 <tr>
<th>Header Cell 1</th>
<th>Header Cell 2</th>
</tr>
<tr>
<td>Standard Cell 1</td>
<td>Standard Cell 2</td>
</tr>
<tr>
<td>Standard Cell 3</td>
<td>Standard Cell 4</td>
</tr>
</table>
</body>
</html>

6.8.1 define a frame;

A frame is a feature in HTML that allows for the division of a web page into multiple sections or
windows. Each frame can display a separate HTML document, allowing different content to be
displayed simultaneously within a single web page. Frames are defined using the <frame> tag
in HTML.

6.8.2 differentiate between a frame and a frameset;

A frame is an individual section or window within a web page, while a frameset is a container
that holds multiple frames. In other words, a frame is a single division or window, whereas a
frameset is the collection of multiple frames. Framesets are defined using the <frameset> tag
in HTML.

6.8.3 create a frameset with multiple frames:

<!DOCTYPE html>
<html>
<head>
<title>My Page Title</title>
</head>
<frameset rows="50%, 50%">
<frame src="frame1.html">
 <frame src="frame2.html">
</frameset>
</html>
(you can also use the attribute 'cols' for columns)