Name:_________________

Subject: ICT Roll

No:__________

Input Devices

Input devices are hardware tools used to send data or commands to a computer
system. They allow users to interact with and control the computer by entering
information such as text, images, sound, or actions. Common input devices include
keyboards for typing, mice for navigation, microphones for audio input, and scanners
for digitizing physical documents. These devices act as the primary means for users to
feed data into a system for processing.

Output Devices

Output devices are used to convey the results of computer processing to the user. They
take data from the computer and convert it into a human-readable or perceivable form.
Monitors display text and graphics visually, printers produce hard copies of digital
content, and speakers play audio. Output devices are essential for allowing users to
view, hear, or print the results of their input and the system's operations.

Input Devices:

1. Keyboard
A keyboard is used to input text, numbers, and commands into a computer.
It consists of keys arranged in a standard layout (QWERTY).
Each key press sends a specific signal to the CPU.
It is essential for typing and controlling software.
Special keys like Ctrl, Alt, and function keys allow shortcuts.

2. Mouse
A mouse controls the pointer on the screen through physical movement.
It has buttons for clicking and a scroll wheel for navigation.
Used to open files, drag objects, and interact with GUIs.
Can be wired or wireless, optical or laser-based.
Some advanced mice include extra buttons for shortcuts.

3. Microphone
A microphone captures audio input from the user.
It converts sound waves into digital signals.
Used in voice recognition, recording, and online communication.
Often used in applications like Zoom, Skype, or gaming.
Can be built-in or external (USB).

4. Scanner
A scanner digitizes physical documents and images.
It converts paper into digital formats like JPEG or PDF.
Used for copying, archiving, or editing documents.

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Flatbed and handheld are two common types.
Often used in offices, schools, and graphic design.

5. Webcam
A webcam captures video and sometimes audio.
It is commonly used for video calls and streaming.
It connects via USB or is built into laptops.
Records video in real-time for communication apps.
Can include features like autofocus and low-light enhancement.

Output Devices:

1. Monitor
A monitor displays visual output from the computer.
It shows text, images, videos, and software interfaces.
Comes in LCD, LED, or OLED types with various resolutions.
It connects via HDMI, VGA, or DisplayPort.
Essential for seeing the results of user input and system processes.

2. Printer
A printer produces physical (hard copy) output from digital files.
It prints documents, photos, and graphics onto paper.
Types include inkjet, laser, and thermal printers.
Used in homes, offices, and schools for documentation.
Can be connected via USB, Wi-Fi, or Bluetooth.

3. Speakers
Speakers output sound produced by the computer.
They convert digital signals into audible sound waves.
Used for music, video, gaming, and system alerts.
Can be built-in or external with stereo or surround sound.
Often connect via audio jack, USB, or Bluetooth.

4. Projector
A projector displays the computer screen onto a wall or screen.
Used in presentations, classrooms, and home theaters.
It enlarges visuals for a bigger audience.
Connects through HDMI, VGA, or wirelessly.
Modern projectors may support HD and smart features.

5. Headphones
Headphones provide private audio output to the user.
Used for music, calls, gaming, or video editing.
Available in wired and wireless versions.
Offers features like noise cancellation and surround sound.
Useful in quiet environments or shared spaces.

What is a Storage Device?

A storage device is a piece of computer hardware used to store, retrieve, and

manage digital data. It holds information such as documents, programs, photos, and

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videos, either temporarily (volatile) or permanently (non-volatile). Storage devices
can be internal (inside the computer) or external (connected from outside), and they
come in many forms like hard drives, SSDs, USB flash drives, memory cards, and
even cloud storage. They are essential for saving your operating system, files, and
software so they can be used again later.

Hard Disk Drive (HDD)

An HDD uses spinning magnetic disks to store data.

It offers high storage capacity at a lower cost.
Commonly used in desktops, laptops, and servers.

Solid State Drive (SSD)

An SSD stores data on flash memory chips with no moving parts.

It is much faster and more durable than HDDs.
Ideal for faster boot times and data access in modern computers.

USB Flash Drive

A small, portable device that uses flash memory.

Used to transfer and store files between computers.
Connects via USB and is plug-and-play.

CD/DVD (Optical Discs)

Stores data using laser technology on a circular disc.

Used for music, videos, software, and backups.
Requires an optical drive to read or write data.

Memory Card (SD Card)

A compact flash-based storage device.

Commonly used in cameras, phones, and handheld devices.
Easily removable and supports fast read/write speeds.

External Hard Drive

A portable HDD or SSD connected via USB or other ports.

Used for backups, extra storage, or transferring large files.
Often used for archiving important data.

Cloud Storage

Stores data on remote servers accessed via the internet.

Services like Google Drive or Dropbox offer online storage.
Allows access from any device with internet connectivity.

Arithmetic Logic Unit (ALU)

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 The ALU performs all arithmetic operations like addition, subtraction, etc.
It also handles logical operations such as comparisons (e.g., greater than, equal to).
This is where actual data processing happens.
The ALU works closely with the control unit to execute instructions.

Control Unit

The control unit manages and coordinates all the operations of the computer.
It tells the memory, ALU, input, and output units what to do and when.
It interprets instructions from the program and directs the system accordingly.
Basically, it acts like a supervisor controlling the entire process.

A memory unit is a standard way to measure the amount of digital data that a computer
can store or process. The smallest unit of memory is a bit, which can hold a binary value
of either 0 or 1. A group of 8 bits makes a byte, which is the basic unit used to represent a
single character, such as a letter or number. As data needs grow, larger units are used: a
kilobyte (KB) is 1,024 bytes, a megabyte (MB) is 1,024 KB, a gigabyte (GB) is 1,024
MB, and a terabyte (TB) is 1,024 GB. Beyond that, there are petabytes (PB), exabytes
(EB), zettabytes (ZB), and yottabytes (YB)—used mainly in data centers and cloud
storage. These units help quantify and manage storage capacity in computers, phones,
and servers, from saving simple text files to storing large databases and videos.

Disk Space Management

Disk space management is a function of an operating system that involves

efficiently allocating, tracking, and freeing up space on a storage device (like a hard
drive or SSD). It ensures that files and directories are stored in a way that minimizes
wasted space and maximizes performance. The system keeps track of which areas of
the disk are in use and which are free, using structures like file allocation tables
(FAT), inodes, or block maps. When a file is created or modified, the OS decides
where to place it, sometimes splitting it across multiple blocks if necessary—a process
known as fragmentation. Disk space management also includes tools for
defragmentation, disk cleanup, and quota management, helping maintain
system speed, prevent storage overflow, and ensure fair use among multiple users.
Proper management helps avoid errors, improves read/write performance, and extends
the life of storage devices.

Defragmentation rearranges fragmented files on a hard drive into contiguous spaces

to speed up access and improve performance. It is mainly used for HDDs, not SSDs.

Disk Cleanup removes unnecessary files like temp files and recycle bin contents to
free up disk space and improve system speed.

Managing the Recycle Bin involves controlling how deleted files are handled before
permanent removal. Users can restore accidentally deleted files from the Recycle Bin,
or empty it to free up disk space. You can also adjust its settings to limit its size or
choose whether files bypass it and get deleted immediately. Proper management helps
prevent data loss while optimizing storage.

Yes, restarting the system often helps! It clears temporary files, resets running
processes, and can fix minor software glitches or performance issues. Restarting can

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 also apply updates and refresh system resources, making your computer run smoother.
So, it’s a simple but effective troubleshooting step.

Searching for a file makes finding what you need much easier and faster, especially
when you have lots of files scattered across folders. Instead of manually browsing, you
can quickly locate a file by name, type, or date using built-in search tools. It saves time
and reduces frustration!

Introduction to Problem Solving through Algorithm and Flowchart

Problem-solving is the process of finding a logical solution to a specific task or

challenge. In computing, we solve problems using algorithms and flowcharts to plan
and visualize the steps before writing actual code.

What is an Algorithm | Introduction to Algorithms

An algorithm is a step-by-step procedure or set of rules designed to solve a specific
problem or perform a specific task.

It takes some input, processes it through a sequence of well-defined instructions, and

produces an output.

Example:
To add two numbers:
1. Start
2. Input number A
3. Input number B
4. Add A and B → Store result in C
5. Output C
6. End
This is a simple algorithm for addition.

 What is a Flowchart?
 A flowchart is a visual representation of a process, algorithm, or system
using symbols and arrows.
It shows the logical flow of steps in a process from start to end.

 It helps in planning, designing, analyzing, and communicating how a program

or system works.

 Why Use Flowcharts?

 Uses:

 Design algorithms

 Document business processes

 Explain program logic

 Debug logical errors

 Teach programming or process design

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  Key Flowchart Symbols (Expanded)
 Symbol  Name  Function

Represents the beginning or end of

Oval Start/End
a flow
Parallelogram Input/Output Shows data input or output
Rectangle Process Indicates an action or operation
Diamond Decision A condition that branches (Yes/No)
Arrow Flowline Shows direction of process flow

 Rules for Making Flowcharts

 Start and End with an oval symbol.

 Keep flow top to bottom or left to right.

 Use arrows to show the correct direction.

 Only one entry and exit point per symbol.

 Label decision branches (Yes/No or True/False).

 Keep it clear and simple — avoid too much clutter.

 Use meaningful names for processes or variables.

 Advantages of Flowcharts

 Makes logic easy to understand

 Useful for problem-solving

 Helps in debugging

 Aids in documentation

 Useful for team communication

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  Limitations of Flowcharts

 Can become complex for large problems

 Not suitable for minor changes (redrawing needed)

 Takes time to draw and update

 How to Find Errors in a Flowchart

 Finding errors in a flowchart means checking if the logic, sequence, symbols, or flow
are incorrect. This is very important before turning the flowchart into a program.