ICT

Chapter 1: Types and Components of Computer Systems

1.1 Hardware and Software

1)Hardware

1. Physical components of a computer system (internal & external).

2. Examples: input (keyboard, mouse), output (monitor, printer), storage devices.

3. Internal hardware includes CPU, RAM, ROM, motherboard, GPU, NIC.

4. Tangible - can be touched, unlike software.

●Motherboard

1.Main circuit board - connects CPU, memory, and all components.

2. Provides slots/sockets for expansion (e.g. graphics card, RAM).

3. Acts as a hub for communication between devices.

4. Made of non-conductive material with printed copper/aluminium circuits.

●CPU (Processor)

1. Executes instructions from software.

2. Made up of ALU (calculations & logic) and CU (controls operations).

3. Often called the "brain of the computer".

4. Determines processing speed of the system

●RAM (Random Access Memory)

1. Volatile memory - contents lost when power off.

2. Stores data, files, and OS currently in use.

3. Can be read and written to.

4. Increases system speed by quick data access.

●ROM (Read-Only Memory)

1. Non-volatile memory - contents retained after power off.

2. Stores permanent data like firmware/ configuration.

3. Can only be read from, not written to.

4. Essential for starting up the computer (boot instructions).

●Graphics Card (GPU)

1. Processes images and video for display.

2. Contains its own processor, memory, and cooling system.

3. Connects to monitor/TV/projector.

4. Improves performance in gaming, design, and video rendering.

●Sound Card

1. Produces audio output through speakers/headphones.

2. Allows sound input via microphones.

3. Enables recording, playback, and editing of sound.

4. Used in multimedia tasks like gaming, music, and video.

●NIC (Network Interface Card)

1. Connects device to a network (wired or wireless).

2. Each NIC has a unique MAC address.

3. Allows data communication between computers.

4. Used in LANs, WANs, and internet access.

●HDD / SSD

1. Main storage devices of a computer.

2. HDD - magnetic storage, cheaper, larger capacity, but slower.

3. SSD - flash storage, faster, durable, no moving parts.

4. Store OS, software, files, and user data.

2) Software

1.Software is a set of instructions that control computer hardware.

2. It cannot be physically touched.

3. Software is divided into system software and applications software.

4. It allows users to perform tasks and run hardware effectively.

●Applications Software

1. Applications software is used to perform specific tasks for the user.

2. Examples include word processing, spreadsheets, databases, and CAD.

3. It can be general-purpose or specialized.

4. Apps and applets are also types of application software.

□Word Processing

1. Word processing software is used to create and edit text documents.

2. It allows formatting, spell checking, and copy-paste functions.

3. Images and tables can be inserted into documents.

4. It is used for essays, reports, and letters.

□Spreadsheet

1. Spreadsheet software organizes numerical data in rows and columns.

2. It can perform calculations using formulas and functions.

3. Graphs and charts can be generated for analysis.

4. It allows modelling and "what-if" calculations.

□Database (DBMS)

1. Database software stores data in tables made of records and fields.

2. Users can add, delete, or modify data.

3. Queries and reports can be generated from the data.

4. It is used for storing and analysing large amounts of information.

□Video Editing

1. Video editing software manipulates video clips to produce new videos.

2. Clips can be rearranged, added, or removed.

3. Colour correction, transitions, and sound can be applied.

4. It is used in filmmaking, vlogging, and multimedia presentations.

□Audio Editing

1. Audio editing software allows manipulation of sound files.

2. Users can cut, merge, adjust volume, and add effects.

3. Files can be converted between formats.

4. It is used to create music, podcasts, or ringtones

□Graphics Editing

1. Graphics software edits images, either bitmap or vector.

2. Bitmap editors manipulate pixels, vector editors manipulate lines and shapes.

3. It is used in design, illustration, and photo editing.

4. Examples include Photoshop and Illustrator

□CAD
1.CAD software helps design 2D and 3D models.

2. Designs can be rotated to view from different angles.

3. It provides accurate measurements and dimensions.

4. It is used in engineering, architecture, and manufacturing.

□Control & Measurement Software

1. It connects computers to sensors to collect data.

The software can compare sensor data to stored data.

3. Signals are sent to control real-world processes.

4. It is used in industrial and scientific applications.

□Apps & Applets

1. Apps are software that performs substantial tasks on a device.

2. Applets are small programs usually embedded in web pages.

3. Apps can be downloaded from app stores.

4. Both improve usability and functionality on devices

●System Software

1. System software manages computer hardware and software resources.

2. It provides a platform for applications to run.

3. Examples include operating systems, compilers, linkers, device drivers, and utilities.

4. It is essential for the overall functioning of the computer.

□Operating System (OS)

1. The OS controls hardware and software operations.

2. It handles input/output, memory, and error management.

3. Provides a user interface for interaction.

4. It manages security such as accounts and passwords.

□Utilities

1. Utilities perform maintenance and optimisation tasks.

2. Examples include antivirus, backup software, and disk repair.

3. They improve computer performance.

4. They protect data and resources.

□Compiler

1. A compiler converts high-level programming code into machine code.

2. Source code is translated into object code for execution.

3. Compiled programs can be reused without recompilation.

4. Examples include compilers for Java, Python, and C++.

□Linker

1. A linker combines different modules into a single executable program.

2. It allows programmers to work on separate modules independently.

3. The linker produces the final program that runs on the computer.

4. It simplifies complex programming tasks.

□Device Driver

1.A device driver enables hardware to communicate with the operating system.

2. Without drivers, hardware like printers and USB devices cannot work.

3. Drivers are installed automatically or manually when hardware is connected.

4. Errors occur if drivers are missing or incompatible.

3) Analogue & Digital Data

1. Analogue data is continuous and varies smoothly over time.

1. Analogue data is continuous and varies smoothly over time.

2. Digital data is discrete and represented in binary (0s and 1s).

3. Analogue-to-digital converters (ADC) change real-world signals into digital form.

4. Digital-to-analogue converters (DAC) change computer signals into real-world outputs like
sound or motor movement.

1.2 The Main Components Of Computer System

●Input Devices

1.Input devices allow data or instructions to be entered into the computer.

2. Examples include keyboards, mice, cameras, microphones, scanners, and sensors.

3. Some input devices may require an analogue-to-digital conversion before the computer can
process the data.

4. Input devices are necessary for the computer to receive commands and information from the
user.

●Output Devices

1. Output devices present the results of computer processing in a human-understandable form.

2. Examples include monitors, printers, speakers, projectors, and plotters.

3. Output devices can receive digital data from the computer and convert it into text, images,
sound, or other formats.

4. They are controlled by the computer to display information or control other devices.

●Differences Between Input and Output Devices

1.Input devices send data to the computer but cannot receive data from it.
2. Output devices receive data from the computer but cannot send data to it.

3. Input devices allow the user to interact with the computer, while output devices allow the
computer to communicate results to the user.

4. Some devices, like touchscreens or DVD writers, can function as both input and output
devices

●Backing Storage (Secondary Storage)

1. Backing storage permanently stores data, programs, and operating systems even when the
computer is off.

2.Examples include internal HDDs, internal SSDs, pen drives, external HDDs/SSDs, and Blu-ray
discs.

3. Backing storage can be fixed (internal) or removable (external), allowing backup and
portability.

4. Data must be transferred to RAM before the CPU can access it, so backing storage is slower
than internal memory.

●Differences Between Backing Storage and Internal Memory

1.RAM and ROM are faster but smaller and more expensive per byte than backing storage.

2. RAM is volatile and temporary, while ROM and backing storage are non-volatile.

3. RAM and ROM are fixed inside the computer, whereas backing storage can be removable or
internal.

4. Backing storage has much larger capacity and stores data permanently, unlike RAM and
ROM.
1.3 Operating Systems

Operating System Advantages Disadvantages

Command Line Interface ●CLI requires users to type ●The user needs to learn a
instructions to run programs number of commands to
or perform tasks using carry out basic operations.
specific commands.
●All commands need to be
●The user is in direct typed in, which takes time
communication with the and can be error- prone.
computer.
●Each command must be
●The user is not restricted to typed in using the correct
a number of pre-determined format, spelling, and so on.
options.

●It is possible to alter

computer configuration
settings.

Graphical User Interface ●●GUI allows users to ●This type of interface uses
interact with the computer up considerably more
using icons, windows, and computer memory than a CLI
menus instead of typing interface.
commands
●The user is limited to the
●The user does not need to icons provided on the screen.
learn any commands.
●Needs a more complex
●It is more user-friendly; operating system, such as
icons are used to represent Windows, to operate, which
applications. can be slower to execute
commands
●A pointing device (such as a
mouse) is used to click on an
icon to launch the application
- this is simpler than typing in
commands.
Dialogue-based interface ●Dialogue-based interfaces ●still unreliable, with many
use voice commands to commands not being
control devices, like smart recognised or needing to be
home systems or cars. repeated several times
(especially if there is
●no need for a driver to take background noise)
their hands off the steering
wheel ●can be quite complex to set
up
● in a home, very useful for
people with disabilities, ●user needs to know which
because many tasks can be commands can be used
carried out by the spoken
word only

●possible to use as a security

feature, because voice
recognition could be used to
identify a person

Gesture-based interface ●Gesture-based interfaces ●possible for unintentional

use human movements, such movement to be picked up
as hands or feet, to control a
device via sensors or ●only works fairly near to the
cameras. camera or sensor (maximum
of 1.5 metres)
●replaces mechanical input
devices ●may only accept a limited
number of movements (for
●no physical contact required example, it may take several
attempts to find out exactly
●> very natural interface for a what finger movements are
human operator recognised)

●no training needed to

interface with the computer
1.4 Types of Computers

Device Name Characteristics Uses Advantages Disadvantages

Desktop Desktop They are mainly lower cost, easy lack of

Computers computers are used for office upgrading, portability,
general-purpose work, education, better complex wiring,
computers made gaming, and performance for and the need to
up of separate entertainment the price, and copy files when
monitor, due to their less risk of theft
keyboard, higher or damage.
mouse, and specifications
processor units, and stable
making them internet
non-portable.. connectivity.

Laptop Laptops They are used portability, Disadvantages

Computer combine the for office work, compact design, include limited
monitor, education, minimal wiring, upgrade options,
keyboard, gaming, and compatibility shorter battery
pointing device, entertainment, with Wi-Fi and life, higher theft
and processor and remote multimedia risk, and
into a single monitoring or systems. sometimes less
portable unit control tasks. comfortable
with long battery keyboards or
life and low pointing devices
power
consumption.

Smartphones Smartphones They include Advantages Disadvantages

are mobile features like include include small
computers with cameras, portability, screens and
an operating sensors, cloud internet access keyboards,
system, allowing storage, anywhere, apps faster battery
them to run Bluetooth, and for multiple drain, limited
apps, access the high-definition functions, and memory, risk of
internet, and use touchscreens. reasonable theft, and slower
multimedia battery life mobile network
features. speeds
compared to
Wi-Fi.

Tablets and Tablets are Phablets are Advantages Disadvantages

Phablets portable hybrid devices include include higher
touch-screen between portability, fast cost, limited
devices with smartphones start-up, easy storage or
virtual and tablets, use via touch memory, slower
keyboards, combining large screens, and typing on
 internet access, screens with the entertainment, touchscreens,
long battery life, features of both gaming, or and reliance
and multiple device types. educational mobile networks
built-in apps. applications. for internet
access.

1.5 Emerging Technologies

●Artificial Intelligence (Al)

Definition:

●Al = computer systems or applications that carry out tasks requiring human intelligence (e.g.
speech, vision, decision-making, problem-solving).

Examples of Al applications:

●Language use (e.g. chatbots, translation apps)

●Face recognition (e.g. unlocking phones, CCTV)

□Positive impacts (advantages):

●Improves safety (e.g. robots in dangerous environments like bomb disposal, nuclear disasters)

●Improves healthcare (e.g. robotic prosthetics, diagnosis support)

●Improves quality of products & services (e.g. automated assembly lines, personalized
recommendations)

●Saves time & efficiency (automation of routine tasks

Negative impacts (disadvantages):

●Job losses (e.g. drivers, factory workers replaced by robots)

●Over-dependence on technology (humans may lose ability to perform basic tasks)

●Loss of skills (traditional skills replaced by machines/software)

●Ethical concerns (bias in Al, decision-making without human control)

■Extended Reality (XR)

Definition: Umbrella term for immersive technologies that blend or replace real & virtual
environments.

Includes Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR) (focus here: AR
+ VR).

□Augmented Reality (AR)

Features:

●Overlays digital info (text, images, animation) on real-world view.

●Enhances real-world experience instead of replacing it.

●Accessible via smartphones, tablets, AR goggles.

●User is not cut off from real world.

Examples:

Safety & rescue: simulate disaster/ rescue missions with 3D mapping.

Entertainment: interactive movies, immersive games.

Shopping/retail: virtual try-ons (clothes, cars, makeup).

Healthcare: 3D body scans for surgery planning & diagnosis.

□Virtual Reality (VR)

Features:

Fully immerses user in a virtual digital world.

Requires VR headset/head-mounted display.

Provides 360° views - tricks brain into believing the simulation is real.

Examples:

VR games, virtual tours, medical training simulations.

Future impacts / Uses:

Military: safe training for tanks, aircraft, combat.

Education: history lessons inside ancient ruins, science labs.

Healthcare: surgical training, diagnostic tools.

Entertainment: fully immersive gaming, VR cinemas.

Fashion: virtual fashion shows before real events.