COMPUTER HARDWARE Lesson Note
This SS1 DIGITAL TECHNOLOGY lesson note covers COMPUTER HARDWARE for First Term, Week 3.
Learning Objectives
- At the end of the lesson, students should be able to:
- Define computer hardware.
- Explain the difference between hardware and software.
- Identify the major components of computer hardware.
- Explain the functions of common input devices.
- Explain the functions of common output devices.
- Identify the major processing components of a computer.
- Explain the functions of storage devices.
- Distinguish between internal and external hardware.
- State the importance of computer hardware.
- State basic ways of caring for computer hardware
Lesson Note
A. MEANING OF COMPUTER HARDWARE
Computer hardware refers to all the physical parts of a computer system that can be seen and touched.
In simple terms, hardware is the physical equipment that makes up a computer system.
Examples of computer hardware include: Monitor, Keyboard, Mouse, System unit, Printer, Scanner, Speakers, Hard disk, Solid-State Drive (SSD), RAM, Motherboard, Processor, Webcam and Flash drive
For example, when you type on a keyboard, the keyboard is hardware because it is a physical device.
B. MAJOR CATEGORIES OF COMPUTER HARDWARE
Computer hardware can be grouped according to the functions it performs.
The major categories are:
1. Input devices
2. Processing devices
3. Output devices
4. Storage devices
5. Communication/networking devices
C. INPUT DEVICES
Input devices are hardware devices used to enter data and instructions into a computer.
Examples of Input Devices:
1. Keyboard
A keyboard is an input device containing keys used for entering letters, numbers, symbols and commands.
Functions
*Typing text
*Entering numbers
*Entering commands
*Using shortcut keys
2. Mouse
A mouse is a pointing device used to control the pointer on the computer screen.
Functions
*Selecting items
*Opening files and programs
*Dragging objects
*Scrolling
*Clicking buttons
3. Scanner
A scanner captures text, photographs or other documents and converts them into digital form.
Uses
*Digitizing documents
*Scanning photographs
*Creating electronic copies of documents
4. Microphone
A microphone captures sound and sends it to a computer.
Uses
*Recording audio
*Voice communication
*Online meetings
*Voice commands
5. Webcam
A webcam is a camera that captures images and video for use with a computer.
Uses
*Video calls
*Online classes
*Video recording
*Video conferencing
6. Touchscreen
A touchscreen allows users to interact with a computer or device by touching areas of the screen.
It can function as both an input and output device.
D. PROCESSING HARDWARE
Processing hardware is responsible for carrying out instructions and manipulating data. The most important processing component is the Central Processing Unit (CPU).
Central Processing Unit (CPU)
The CPU is the main processor of a computer. It executes instructions and performs calculations.
It is commonly referred to as the brain of the computer.
Major parts of the CPU
Arithmetic and Logic Unit (ALU)
Control Unit (CU)
Registers
1. Arithmetic and Logic Unit
The ALU performs: Addition, Subtraction, Multiplication, Division, Comparisons and Logical operations
2. Control Unit
The Control Unit coordinates the activities of the computer.
It:
*Fetches instructions.
*Decodes instructions.
*Controls their execution.
*Coordinates other components.
3. Registers
Registers are very small, high-speed storage locations inside the CPU. They temporarily hold data and instructions currently being processed.
4. MOTHERBOARD
The motherboard is the main circuit board of a computer.
It provides connections through which important components communicate with one another.
Components that may connect to the motherboard include: CPU, RAM, Storage devices, Graphics hardware, Expansion cards, USB and other ports
Functions of the motherboard
i. Connects major computer components.
ii. Allows components to communicate.
iii. Provides pathways for data transfer.
iv. Distributes electrical power to components through appropriate connections.
5. MEMORY HARDWARE
Memory is used to hold data and instructions needed by the computer.
Random Access Memory (RAM)
RAM is temporary working memory used by the computer while programs are running.
It is generally volatile, meaning its contents are lost when the computer is switched off.
Importance of RAM
i. Helps programs run.
ii. Holds active data.
iii. Supports multitasking.
iv. Provides quick access to information being used.
6. STORAGE DEVICES
Storage devices are used to keep data and programs for future use.
Unlike RAM, storage devices normally retain their information when the computer is turned off.
Examples: Hard Disk Drive (HDD), Solid-State Drive (SSD), USB flash drive,Memory card and Optical disc
HARD DISK DRIVE (HDD)
An HDD is a storage device that uses magnetic disks to store data.
Uses
i. Storing operating systems
ii. Storing documents
iii. Storing photographs
iv. Storing videos
v. Storing applications
SOLID-STATE DRIVE (SSD)
An SSD is a storage device that uses electronic flash memory rather than spinning magnetic disks.
Advantages of SSD
*Generally faster than traditional HDDs.
*Has no moving mechanical disk.
*Usually operates quietly.
*Can improve system startup and application loading times.
USB FLASH DRIVE
A USB flash drive is a small portable storage device that connects to a computer through a USB port.
Uses
i. Storing files
ii. Transferring files
iii. Creating backups
iv. Moving data between compatible devices
E. OUTPUT DEVICES
Output devices are hardware components used to present processed information to the user.
Examples:
1. Monitor
A monitor displays text, images, videos and other information.
2. Printer
A printer produces information on paper. This is called hard copy.
3. Speakers
Speakers produce sound from the computer.
4. Projector
A projector displays computer information onto a larger surface, such as a screen or wall.
5. Headphones
Headphones allow users to listen to sound privately.
F. COMMUNICATION AND NETWORKING HARDWARE
Communication hardware allows computers and other digital devices to communicate with each other.
Examples: Network Interface Card (NIC), Modem, Router, Network switch and Wireless network adapter
1. Network Interface Card (NIC)
*A NIC allows a computer to connect to a network.
*It may provide either wired or wireless network connectivity.
2. Router
A router directs data between different networks. In homes and schools, routers are commonly used to connect devices to a local network and the Internet.
3. Network Switch
A switch connects multiple devices within a network and forwards data to the appropriate device.
4. Modem
A modem converts signals in ways that allow a device or network to communicate with an Internet service provider or other communication system, depending on the technology being used.
G. INTERNAL AND EXTERNAL HARDWARE
Internal Hardware
Internal hardware components are found inside the computer system.
Examples include: CPU, RAM, Motherboard, Internal HDD, Internal SSD, Power supply unit, Cooling fan
External Hardware
External hardware refers to devices connected to or used with the computer from outside the main system.
Examples include: Keyboard, Mouse, Monitor, Printer, Speakers, Webcam External hard drive and USB flash drive
H. COMPUTER PORTS AND CONNECTORS
A port is a connection point through which devices can communicate with or connect to a computer.
Common ports include:
USB Port
Used to connect devices such as:
*Flash drives
*Keyboards
*Mice
HDMI Port
Used mainly to transmit digital video and audio to compatible displays.
Ethernet Port
Used for wired network connections.
Audio Port
Used to connect headphones, microphones and other audio equipment.
USB-C
A modern reversible connector used for various purposes, including data transfer and, on supported devices, charging and display connections.
I. GRAPHICS PROCESSING UNIT (GPU)
A Graphics Processing Unit (GPU) is a processor designed to handle graphics and other highly parallel calculations.
Uses of a GPU
1. Displaying graphics
2. Video editing
3. Computer-aided design
4. 3D modelling
5. Scientific and engineering applications
6. Some artificial intelligence workloads
7. Some computers have integrated graphics, while others have dedicated graphics hardware.
J. 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 power for computer components.
Importance
Without an appropriate power supply, the computer’s internal components cannot operate properly.
K. COOLING HARDWARE
Computer components produce heat during operation.
Cooling hardware helps remove excess heat and maintain suitable operating temperatures.
Examples: Cooling fans, Heat sinks, Thermal interface materials and Liquid-cooling systems in some computers
Importance of cooling
1. Helps prevent overheating.
2. Supports stable computer operation.
3. Helps protect components.
4. Can reduce performance problems caused by excessive heat.
L. CARE AND MAINTENANCE OF COMPUTER HARDWARE
Proper care can increase the useful life of computer hardware.
Good maintenance practices include:
1. Keep computers in a clean and dry environment.
2. Keep liquids away from computer equipment.
3. Avoid blocking ventilation openings.
4. Handle laptops and other portable devices carefully.
5. Keep keyboards and screens clean using appropriate methods.
6. Use suitable electrical protection where necessary.
7. Avoid pulling cables roughly.
8. Shut down computers properly when appropriate.
9. Keep vents and cooling areas free from excessive dust.
10. Allow qualified personnel to perform internal repairs when necessary.
M. IMPORTANCE OF COMPUTER HARDWARE
Computer hardware is important because it:
1. Allows users to enter data.
2. Processes data.
3. Stores information.
4. Displays results.
5. Produces printed documents.
6. Enables communication.
7. Supports Internet connectivity.
8. Allows multimedia activities
9. Supports education and research.
10. Enables businesses and organizations to perform digital tasks.
SUMMARY
Computer hardware refers to the physical components of a computer system that can be seen and touched.
Computer hardware can be classified into input, processing, output, storage and communication/networking hardware.
Input devices such as keyboards, mice and scanners enter data into the computer. The CPU processes instructions, while the motherboard connects many of the major components. RAM provides temporary working memory, while HDDs, SSDs and flash drives provide long-term storage.
Output devices such as monitors, printers and speakers present processed information to users. Networking hardware such as NICs, routers and switches enables computers to communicate.
Proper care and maintenance of hardware helps ensure reliable operation and can extend the useful life of computer equipment.
Evaluation
OBJECTIVE QUESTIONS
1. Which of the following best describes computer hardware?
A. Computer instructions
B. Physical components of a computer
C. Internet websites
D. Computer passwords
2. Which of the following is an input device?
A. Monitor
B. Printer
C. Keyboard
D. Speaker
3. Which component is mainly responsible for processing instructions?
A. CPU
B. Monitor
C. Keyboard
D. Printer
4. Which part of the CPU performs arithmetic and logical operations?
A. Control Unit
B. ALU
C. Register
D. Motherboard
5. Which of the following is generally a volatile memory?
A. RAM
B. SSD
C. Flash drive
D. Hard disk
6. Which device is mainly used to display information from a computer?
A. Scanner
B. Keyboard
C. Mouse
D. Monitor
7. Which of the following is a storage device?
A. Microphone
B. SSD
C. Monitor
D. Keyboard
8. What is the main function of a motherboard?
A. To print documents
B. To display pictures
C. To connect and allow communication between major components
D. To record sound
9. Which hardware device is commonly used to connect a computer to a wired network?
A. Ethernet port/NIC
B. Speaker
C. Scanner
D. Projector
10. Which of the following is a good practice for protecting computer hardware?
A. Pouring liquid near the computer
B. Blocking the ventilation openings
C. Keeping the computer clean and properly ventilated
D. Pulling cables forcefully
Theory Questions
1a. What is computer hardware? List ten examples of computer hardware.
1b. Explain the difference between hardware and software, giving three examples of each.
2a. Describe the functions of the following:
i) Keyboard ii) Mouse iii) CPU iv)Monitor v) Printer.
2b. Differentiate between RAM and secondary storage, giving two examples of secondary storage devices.
2c). State ten ways of caring for and maintaining computer hardware.