BASIC COMPUTER HARDWARE COMPONENTS Lesson Note
This SS1 COMPUTER HARDWARE AND GSM REPAIR lesson note covers BASIC COMPUTER HARDWARE COMPONENTS for First Term, Week 4.
Learning Objectives
- At the end of the lesson, students should be able to:
- 1. Define computer hardware.
- 2. Explain the difference between hardware and software.
- 3. Identify the major hardware components of a computer.
- 4. State the functions of common computer hardware components.
- 5. Differentiate between input, output, processing and storage devices.
- 6. Identify the major components found inside a computer system unit.
- 7. Explain the importance of each major hardware component.
- 8. Handle computer hardware components carefully and safely.
Lesson Note
A. Meaning of Computer Hardware
Computer hardware refers to the physical parts of a computer system that can be seen and touched.
Examples include: Keyboard, Mouse, Monitor, System unit, Printer, Scanner, Speakers, Hard disk drive, Solid-state drive, RAM, Motherboard, Processor (CPU), Power Supply Unit (PSU) and Webcam
Hardware works together with software to enable a computer to perform different tasks.
B. Hardware and Software
1. HARDWARE
Hardware is the physical part of a computer, while software consists of the programs and instructions that tell the hardware what to do.
For example:
- Keyboard → Hardware
- Monitor → Hardware
- Windows → Software
- Microsoft Word → Software
- Calculator application → Software
A computer needs both hardware and software to function effectively.
Major Categories of Computer Hardware
Computer hardware can be grouped into four major categories:
1. Input devices
2. Output devices
3. Processing devices
4. Storage devices
1. Input Devices
Input devices are hardware components used to enter data and instructions into a computer.
Examples of Input Devices:
i. Keyboard
A keyboard is an input device containing keys used to enter letters, numbers, symbols and commands into a computer.
Functions of a Keyboard
- Typing letters and words
- Entering numbers
- Entering symbols
- Issuing commands
- Controlling certain computer functions
Common keyboard keys include:
- Alphabet keys
- Number keys
- Function keys
- Enter key
- Spacebar
- Shift key
- Ctrl key
- Alt key
- Backspace
- Delete
- Arrow keys
2. Mouse
A mouse is a pointing input device used to control the movement of the pointer or cursor on a computer screen.
Functions of a Mouse
- Selecting items
- Opening files and programs
- Dragging objects
- Scrolling through documents
- Right-clicking for additional options
Common mouse actions include:
- Single-click
- Double-click
- Right-click
- Drag and drop
- Scrolling
3. Scanner
A scanner is an input device used to convert printed documents, photographs or images into digital form that can be processed by a computer.
Uses of a Scanner
- Scanning documents
- Digitizing photographs
- Creating electronic copies of documents
- Scanning forms and records
4. Microphone
A microphone is an input device that captures sound and sends it to the computer.
Uses
- Voice recording
- Video conferencing
- Online classes
- Voice commands
- Audio production
5. Webcam
A webcam is a camera used to capture images and video and send them to a computer.
Uses
- Video calls
- Online meetings
- Online classes
- Taking pictures
- Recording videos
2. Output Devices
Output devices are hardware components that present processed information from the computer to the user.
Examples
- Monitor
- Printer
- Speakers
- Projector
- Headphones
i. Monitor
A monitor is an output device that displays text, pictures, videos and other information produced by a computer.
It Is sometimes called a Visual Display Unit (VDU).
Functions of a Monitor
- Displays text
- Displays images
- Displays videos
- Shows computer programs
- Allows users to see the results of computer operations
Examples include:
- LCD monitors
- LED monitors
- OLED displays
ii. Printer
A printer is an output device that produces a physical copy of information stored or processed by a computer.
The physical copy Is called a hard copy.
Types of Printers
1. Inkjet printer
2. Laser printer
3. Dot-matrix printer
Uses
- Printing documents
- Printing photographs
- Printing reports
- Printing school materials
iii. Speakers
Speakers are output devices that produce sound from a computer.
They are used for:
- Playing music
- Watching videos
- Hearing notifications
- Online meetings
- Listening to recorded audio
iv. Projector
A projector is an output device that displays computer information on a large screen or wall.
It is commonly used in:
- Classrooms
- Offices
- Conferences
- Presentations
3. Processing Components
Processing components are responsible for manipulating and processing data according to instructions.
The most important processing component is the Central Processing Unit (CPU).
i. Central Processing Unit (CPU)
The CPU is the main processing unit of a computer. It interprets and executes instructions and performs calculations.
It is often referred to as the brain of the computer.
Major Parts of the CPU
The CPU contains important units such as:
a. Arithmetic and Logic Unit (ALU)
b. Control Unit (CU)
c. Registers
Arithmetic and Logic Unit (ALU)
a. The ALU performs:
- Arithmetic operations such as addition, subtraction, multiplication and division.
- Logical operations such as comparing values.
b. Control Unit (CU)
The Control Unit controls and coordinates the activities of other components of the computer.
It tells different parts of the computer what operations to perform.
c. Registers
Registers are very small, high-speed storage locations inside the CPU used to temporarily hold data, instructions and results during processing.
ii. Motherboard
The motherboard is the main circuit board of a computer.
It provides connections between many computer components.
Components connected to the motherboard may include:
- CPU
- RAM
- Storage devices
- Expansion cards
- USB ports
- Power connectors
- Other peripheral devices
Functions of the Motherboard
1. Connects major computer components.
2. Allows components to communicate with one another.
3. Provides pathways for electrical signals.
4. Provides slots and connectors for various hardware devices.
5. Supports the operation of the CPU, RAM and other components.
iii. Random Access Memory (RAM)
RAM stands for Random Access Memory.
It is a type of temporary or volatile memory used by the computer to hold data and programs that are currently being used.
Characteristics of RAM
- It is fast.
- It is temporary.
- Its contents are normally lost when power is switched off.
- More RAM can help a computer handle more programs simultaneously, depending on the system.
Functions of RAM
- Temporarily stores data being processed.
- Holds programs currently in use.
- Helps the CPU access active data quickly.
iv. Storage Devices
Storage devices are hardware components used to store data, programs and files.
Unlike RAM, storage devices retain information even when the computer is turned off.
Examples
- Hard Disk Drive (HDD)
- Solid-State Drive (SSD)
- USB flash drive
- Memory card
- Optical disc
a. Hard Disk Drive (HDD)
A Hard Disk Drive is a storage device that uses magnetic disks to store data.
Uses
- Storing operating systems
- Storing applications
- Storing documents
- Storing photographs
- Storing videos and music
b. Solid-State Drive (SSD)
An SSD is a storage device that uses flash memory to store data.
Unlike a traditional HDD, it has no spinning magnetic disks.
Advantages of SSD
- Generally faster than HDDs
- No moving mechanical parts
- Usually quieter
- More resistant to physical shock
- Can improve system startup and application loading times
c. USB Flash Drive
A USB flash drive is a small portable storage device that connects to a computer through a USB port.
Uses
- Transferring files
- Storing documents
- Backing up files
- Moving data between computers
d. Power Supply Unit (PSU)
The Power Supply Unit (PSU) supplies electrical power to the internal components of a desktop computer.
It converts electrical power from the wall outlet into suitable forms of power required by the computer’s internal components.
Functions of PSU
- Supplies power to the motherboard.
- Supplies power to storage devices.
- Supplies power to cooling fans.
- Supplies power to other internal components.
A faulty PSU can cause a computer to fail to start or shut down unexpectedly.
e. Cooling Fan and Heat Sink
Computer components, especially the CPU, produce heat during operation.
A heat sink absorbs and transfers heat away from a component, while a cooling fan helps move air and remove heat.
Importance of Cooling
Proper cooling:
- Prevents overheating.
- Helps maintain stable operation.
- Protects components.
- Improves system reliability.
f. Graphics Processing Unit (GPU)
A Graphics Processing Unit (GPU) is a processor designed to handle graphics and other highly parallel computing tasks.
It may be:
- Integrated into the processor or motherboard platform.
- A separate graphics card installed in an expansion slot.
Uses of a GPU
- Rendering images
- Displaying graphics
- Playing computer games
- Video editing
- 3D modelling
- Some scientific and artificial intelligence workloads
g. Expansion Cards
An expansion card is a circuit board that can be installed into an appropriate slot on the motherboard to add or improve a computer’s capabilities.
Examples include:
- Graphics card
- Sound card
- Network interface card
Uses
Expansion cards can provide:
- Improved graphics
- Better audio
- Network connectivity
- Additional hardware functions
h. Network Interface Card (NIC)
A Network Interface Card (NIC) is hardware that enables a computer to connect to a network.
A NIC may support:
- Wired Ethernet connections
- Wireless networking, depending on the device
Uses
- Connecting computers to local networks
- Accessing network resources
- Connecting to the internet through a network
i. Ports and Connectors
Ports are physical connection points through which external devices can be connected to a computer.
Common Computer Ports
1. USB port – connects devices such as flash drives, keyboards and mice.
2. HDMI port – carries digital video and audio to compatible displays.
3. Ethernet port – connects a computer to a wired network.
4. Audio ports – connect speakers, headphones or microphones.
5. DisplayPort – carries digital video and audio to compatible displays.
j. System Unit
The system unit is the main enclosure of a desktop computer that contains important internal components.
These may include:
- Motherboard
- CPU
- RAM
- Storage devices
- Power Supply Unit
- Cooling fans
- Expansion cards
The system unit should not be confused with the entire computer system because devices such as the monitor, keyboard and mouse are external components.
k. Peripheral Devices
A peripheral device is a hardware device connected to a computer to provide input, output, storage or additional functions.
Examples include:
- Keyboard
- Mouse
- Printer
- Scanner
- Webcam
- Speakers
- External storage devices
C. Classification of Basic Hardware Components
Category| Examples| Main Function
Input devices| Keyboard, mouse, scanner, microphone| Enter data
Output devices| Monitor, printer, speakers, projector| Present information
Processing devices| CPU, GPU| Process data
Memory| RAM| Temporarily hold active data
Storage| HDD, SSD, flash drive| Store data permanently
Communication devices| NIC, Wi-Fi adapter| Connect to networks
Power components| PSU| Supply electrical power
D. Difference Between RAM and Storage
RAM| Storage
Temporary memory| Long-term data storage
Usually volatile| Non-volatile
Used for active programs and data| Stores files and programs
Very fast| Speed varies by device
Data is normally lost when power is removed| Data remains after power is removed
E. Importance of Computer Hardware
Computer hardware is important because it:
1. Allows users to enter data.
2. Processes data and instructions.
3. Displays information.
4. Stores files and programs.
5. Allows computers to communicate with other devices and networks.
6. Provides sound and visual output.
7. Enables computers to perform specialized tasks.
F. Basic Care and Maintenance of Computer Hardware
To keep computer hardware in good condition:
1. Keep the computer clean and free from excessive dust.
2. Keep liquids away from electronic components.
3. Handle components carefully.
4. Avoid pulling cables forcefully.
5. Ensure adequate ventilation.
6. Do not block cooling vents.
7. Shut down the computer properly.
8. Protect equipment from electrical problems using suitable power protection.
9. Keep food and drinks away from the computer.
10. Allow trained personnel to handle internal repairs when necessary.
Summary
Computer hardware consists of the physical parts of a computer that can be seen and touched. The major categories are input devices, output devices, processing components, memory, storage devices and communication devices.
Important hardware components include the keyboard, mouse, monitor, printer, CPU, motherboard, RAM, HDD, SSD, PSU, GPU, cooling system and network interface devices.
Each component performs a particular function, but they work together as a complete computer system.
Evaluation
OBJECTIVE QUESTIONS
Choose the correct answer from options A–D.
1. Which of the following is a hardware component of a computer?
A. Microsoft Word
B. Windows
C. Keyboard
D. Antivirus program
2. Which device is mainly used for entering text into a computer?
A. Monitor
B. Keyboard
C. Printer
D. Speaker
3. The main processing unit of a computer is the ______.
A. CPU
B. Monitor
C. Keyboard
D. Printer
4. Which of the following is an output device?
A. Mouse
B. Scanner
C. Keyboard
D. Monitor
5. What does RAM stand for?
A. Read Access Memory
B. Random Access Memory
C. Rapid Application Memory
D. Random Application Machine
6. Which component connects many major parts of a computer together?
A. Motherboard
B. Mouse
C. Printer
D. Speaker
7. Which of the following is mainly used for long-term storage of computer files?
A. RAM
B. CPU
C. SSD
D. Register
8. Which component supplies electrical power to the internal parts of a desktop computer?
A. GPU
B. PSU
C. RAM
D. Keyboard
9. Which device is used to produce a physical copy of a document?
A. Scanner
B. Printer
C. Monitor
D. Webcam
10. Which of the following is used to connect a computer to a wired network?
A. Ethernet port
B. Audio port
C. Keyboard key
D. Power button
Theory Questions
1a. What is computer hardware? Give five examples of computer hardware components.
1b. Explain the difference between input devices and output devices. Give three examples of each.
2a. State and explain three major functions of the CPU.
2b. Differentiate between RAM and storage devices.
2c. List five internal components of a computer system unit and state one function of each.