Introduction to ICT Systems
An ICT system (Information and Communication Technology system) is an
integrated set of hardware, software, data, people, and procedures used to collect,
process, store, and communicate information.
ICT systems are used in many sectors such as:

Education (E-learning systems)

Banking (ATM and online banking)

Healthcare (patient management systems)

Government (digital services)

Communication (email and social media)
Basic ICT System Model
Every ICT system follows the Input – Process – Output – Storage (IPOS) model.
Input → Processing → Output
Input
↓
Processing
Output
Storage
Explanation
Storage
Component
Description
Input
Data entered into the system
Processing
Manipulation or calculation of data
Output
Results produced by the system
Storage
Saving data for future use
COMPUTER HARDWARE
Computer hardware refers to the physical components of a computer system that can
be seen and touched.
Examples include:

Keyboard

Mouse

Monitor

CPU

Hard disk

Printer

Speakers
Hardware can be categorized into four major groups:
1. Input Devices
2. Processing Devices
3. Output Devices
4. Storage Devices
3. Input Devices
Input devices are hardware components used to enter data and instructions into a
computer system. They convert human-readable input into machine-readable data.
Common input devices include:

Keyboard

Mouse

Scanner

Microphone

Webcam

Touchscreen

Barcode reader

Biometric devices
Input devices act as an interface between the user and the computer system.
Examples of Input Devices
1. Keyboard
The keyboard is the most common input device used to enter:

Text

Numbers

Symbols

Commands
Types of keys:

Alphabet keys

Numeric keys

Function keys (F1–F12)

Control keys (Ctrl, Alt, Shift)

Navigation keys
2. Mouse
A mouse is a pointing device used to:

Move the cursor

Select objects

Open files

Drag and drop items
Types of mouse:

Optical mouse

Laser mouse

Wireless mouse
3. Scanner
A scanner converts printed documents and images into digital format.
Types:

Flatbed scanner

Handheld scanner

Sheet-fed scanner
4. Microphone
A microphone captures sound and converts it into digital signals that a computer can
process.
Used in:

Online meetings

Voice recording

Voice recognition systems
5. Webcam
A webcam captures video and images and sends them to the computer.
Used in:

Video conferencing

Online learning

Security monitoring
4. Output Devices
Output devices are hardware components that display or present processed
information to the user.
Examples include:

Monitor

Printer

Speakers

Projector

Headphones
Examples of Output Devices
1. Monitor
A monitor (Visual Display Unit – VDU) displays information such as:

Text

Images

Videos

Graphics
Types of monitors:

CRT (Cathode Ray Tube)

LCD (Liquid Crystal Display)

LED (Light Emitting Diode)
2. Printer
A printer produces hard copies of digital documents.
Types:
Type
Description
Inkjet printer
Uses ink cartridges
Laser printer
Uses laser technology
Dot matrix printer Uses impact printing
3. Speakers
Speakers convert digital audio signals into sound.
Used for:

Music

Multimedia

Video conferencing
4. Projector
A projector displays images from a computer onto a large screen.
Common in:

Classrooms

Conference rooms

Presentations
Processing Devices
Central Processing Unit (CPU)
The CPU (Central Processing Unit) is the brain of the computer.
It performs:

Calculations

Logical operations

Data processing

Program execution
CPU Components
+----------------------+
|
CPU
|
|----------------------|
| Control Unit (CU)
|
| Arithmetic Logic Unit (ALU)
| Registers
|
|
+----------------------+
Control Unit (CU)
The Control Unit coordinates the activities of the computer.
Functions:

Fetch instructions from memory

Decode instructions

Control execution
Arithmetic Logic Unit (ALU)
The ALU performs:

Mathematical calculations

Logical comparisons
Examples:

Addition

Subtraction

Greater than / Less than
Registers
Registers are small high-speed storage locations inside the CPU used during
processing.
6. Storage Devices
Storage devices are used to store data, programs, and information for future use.
Storage is divided into:
1. Primary Storage (Main Memory)
2. Secondary Storage
Primary Storage
Primary memory is directly accessed by the CPU.
Examples:

RAM

ROM

Cache memory
RAM (Random Access Memory)
Characteristics:

Temporary memory

Fast access speed

Volatile (data lost when power is off)
ROM (Read Only Memory)
Characteristics:

Permanent memory

Stores startup instructions (BIOS)
Secondary Storage
Secondary storage stores data permanently.
Examples:

Hard Disk Drive (HDD)

Solid State Drive (SSD)

USB Flash Drive

CD/DVD

Memory Card
Computer
Secondary storage is slower but has larger capacity.
7. Software
Hardwar
Software
COMPUTER SOFTWARE
Definiti
System Software
Application Software
Software refers to programs and instructions that control the operation of a
computer system.
Hardware cannot function without software.
Example:

A keyboard cannot process text unless software interprets the input.
Relationship Between Hardware and Software
are
User
↓
Application Software
↓
System Software
↓
Hardware
Software acts as a bridge between the user and hardware.
8. Types of Software
Software is divided into two main categories:
1. System Software
2. Application Software
9. System Software
Definition
System software manages computer hardware and provides an environment for
running application software.
Examples include:

Operating systems

Device drivers

Utility programs
Operating System (OS)
The Operating System is the most important system software.
Examples:

Windows

Linux

macOS

Android

iOS
Functions of the OS:
Function
Description
Process management
Controls running programs
Memory management Manages RAM
File management
Organizes files and folders
Device management
Controls hardware devices
Security
Protects system data
10. Application Software
Definition
Application software is designed to help users perform specific tasks.
Examples include:
Application
Function
Microsoft Word
Word processing
Microsoft Excel
Spreadsheet calculations
PowerPoint
Presentations
Web browsers
Internet access
Database software Data management
Types of Application Software
1. General-purpose software
Used for everyday tasks.
Examples:

Word processors

Spreadsheets

Presentation tools
2. Specialized software
Designed for specific industries.
Examples:

Hospital management systems

Accounting software

Engineering design software
11. Difference Between Hardware and Software
Hardware
Software
Physical components
Programs and instructions
Can be touched
Cannot be touched
Examples: CPU, keyboard Examples: Windows, Word
Manufactured
Developed by programmers