1. Learning Objectives
By the end of this lesson, students should be able to:
- Define a peripheral device.
- Explain the role of peripheral devices in a computer system.
- Classify peripherals into input, output, storage and communication devices.
- Identify common peripheral devices and their functions.
- Differentiate between input and output peripherals.
- Explain why some peripherals can perform both input and output functions.
- Understand the role of ports, interfaces and device drivers.
- Select appropriate peripheral devices for different tasks.
2. What is a Peripheral Device?
A peripheral device is a hardware device connected to a computer system to provide additional input, output, storage or communication capabilities.
Peripherals extend the functionality of a computer and allow users or other systems to interact with it.
Keyboard, mouse, monitor, printer, scanner, webcam, speakers, external hard drive, USB flash drive and network adapter.
3. Role of Peripheral Devices
A computer by itself needs mechanisms to receive information, present results, store data and communicate with other systems. Peripheral devices provide many of these mechanisms.
Storage and communication peripherals can support the system throughout this process.
4. Classification of Peripheral Devices
| Category | Purpose | Examples |
|---|---|---|
| Input Peripherals | Enter data or instructions into a computer. | Keyboard, mouse, scanner, microphone, webcam |
| Output Peripherals | Present information produced by a computer. | Monitor, printer, speakers, projector |
| Storage Peripherals | Store data and programs for later use. | External SSD, external HDD, USB flash drive, memory card |
| Communication Peripherals | Enable computers to communicate with other devices or networks. | Network adapter, Wi-Fi adapter, Bluetooth adapter |
| Input/Output Peripherals | Can both receive and send data. | Touchscreen, multifunction printer, external storage |
5. Input Peripheral Devices
An input peripheral is a device used to provide data or instructions to a computer system.
| Device | Function | Common Application |
|---|---|---|
| Keyboard | Enters text, numbers, symbols and commands. | Typing documents and programs. |
| Mouse | Controls the pointer and allows selection and interaction with graphical interfaces. | Selecting files and operating software. |
| Scanner | Converts physical documents or images into digital data. | Digitising photographs and documents. |
| Microphone | Captures sound. | Voice recording and video conferencing. |
| Webcam | Captures still images and video. | Video meetings and online classes. |
| Barcode Scanner | Reads machine-readable product codes. | Supermarket billing and inventory systems. |
| Biometric Scanner | Captures biometric characteristics. | Fingerprint-based authentication. |
| Joystick / Game Controller | Sends directional and control input. | Games and simulations. |
6. Keyboard
What is a Keyboard?
A keyboard is an input peripheral containing keys used to enter characters, numbers, symbols and commands.
Common Key Groups
- Alphanumeric keys
- Function keys
- Navigation keys
- Control keys
- Numeric keypad
- Special-purpose keys
Pressing Ctrl + S in many applications invokes
the Save command.
7. Mouse and Pointing Devices
A mouse is a pointing device used to control the graphical pointer on a screen.
Common Mouse Actions
- Point
- Click
- Double-click
- Right-click
- Drag and drop
- Scroll
Touchpads and trackballs are other examples of pointing devices.
8. Scanner
A scanner captures the content of a physical document or image and converts it into a digital representation.
Applications
- Digitising documents.
- Scanning photographs.
- Creating digital records.
- Optical Character Recognition (OCR) workflows.
A school can scan a paper certificate and store the resulting digital image in its electronic records.
9. Microphone and Webcam
Microphone 🎙️
Captures sound and converts it into an electrical or digital signal that can be processed by a computer.
Uses: voice recording, online meetings, speech recognition and multimedia production.
Webcam 📷
Captures images and video for processing or transmission by a computer.
Uses: video conferencing, online classes and content creation.
10. Biometric Input Devices
Biometric devices capture measurable biological or behavioural characteristics for identification or authentication.
Examples
- Fingerprint scanner
- Face recognition camera
- Iris recognition device
- Voice recognition systems
11. Output Peripheral Devices
An output peripheral presents information generated by a computer to a user or another system.
| Device | Output | Application |
|---|---|---|
| Monitor | Visual information | Displaying documents, images and video |
| Printer | Printed information | Hard-copy documents and images |
| Speakers | Audio | Music, alerts and multimedia |
| Headphones | Audio | Private listening |
| Projector | Large visual display | Classrooms, meetings and presentations |
12. Monitor
A monitor is a visual output peripheral that displays information generated by the computer.
Common Display Technologies
| Technology | Characteristics |
|---|---|
| CRT | Older cathode-ray-tube technology; bulky and relatively heavy. |
| LCD | Uses liquid crystals and a backlight to produce an image. |
| LED | Commonly refers to an LCD display using LED backlighting. |
| OLED | Uses self-emitting pixels and does not require a conventional LCD backlight. |
13. Printer
A printer converts digital content into a physical printout.
Types of Printers
| Type | Category | Characteristics |
|---|---|---|
| Dot Matrix | Impact | Uses pins striking an ink ribbon. |
| Daisy Wheel | Impact | Uses a character wheel and impact mechanism. |
| Inkjet | Non-impact | Deposits tiny droplets of ink onto paper. |
| Laser | Non-impact | Uses toner and electrostatic imaging; suitable for high-volume document printing. |
14. Audio Output Devices
Speakers 🔊
Speakers convert electrical or digital audio signals into sound that can be heard by users.
Headphones 🎧
Headphones provide audio output directly to an individual listener.
Applications
- Music playback
- Video and multimedia
- Online classes
- Video conferencing
- Accessibility features
- Computer-generated alerts
15. Projector
A projector displays computer-generated visual content on a large screen or surface.
Uses in Education
- Displaying presentations.
- Showing educational videos.
- Demonstrating software.
- Displaying diagrams and simulations.
- Supporting collaborative classroom activities.
16. Storage Peripheral Devices
Storage peripherals provide additional or removable storage capacity for data and programs.
| Device | Technology | Typical Use |
|---|---|---|
| USB Flash Drive | Flash memory | Portable file transfer and storage |
| External HDD | Magnetic storage | Large-capacity backup and storage |
| External SSD | Flash memory | Fast portable storage |
| Memory Card | Flash memory | Storage in cameras and other portable devices |
| Optical Disc | Optical storage | Distribution or archival storage in some contexts |
17. USB Devices
USB (Universal Serial Bus) is a standard interface used to connect many peripherals to computers.
USB Can Be Used With:
- Keyboards
- Mice
- Printers
- External storage
- Webcams
- Microphones
- Game controllers
USB can carry data and, depending on the implementation, can also provide electrical power to connected devices.
18. Communication Peripheral Devices
Communication peripherals enable a computer to exchange data with other computers, devices or networks.
| Peripheral | Purpose |
|---|---|
| Ethernet Adapter | Provides wired network connectivity. |
| Wi-Fi Adapter | Provides wireless network connectivity. |
| Bluetooth Adapter | Enables short-range wireless communication with compatible devices. |
| Modem | Provides communication over certain network access technologies by converting signals as required. |
19. Input/Output Peripherals
Some peripherals perform both input and output functions.
| Device | Input Function | Output Function |
|---|---|---|
| Touchscreen | Detects touch gestures. | Displays visual information. |
| Multifunction Printer | Scans documents. | Prints documents. |
| External Storage | Reads data from storage. | Writes data to storage. |
| Network Adapter | Receives network data. | Sends network data. |
20. Touchscreen
A touchscreen combines a display with a touch-sensitive input system.
It therefore acts as both an output and input interface.
On a smartphone, the screen displays an application while simultaneously detecting taps, swipes and other gestures.
21. Multifunction Printer
A multifunction printer (MFP) combines multiple functions, commonly printing, scanning and copying, and sometimes faxing.
It can therefore provide both input and output functionality.
22. Device Drivers
A device driver is software that enables an operating system and applications to communicate with a particular hardware device.
When a computer sends a print job to a printer, the operating system uses appropriate software support to communicate with the printer.
23. Ports and Interfaces
A peripheral must connect to a computer through an appropriate physical or wireless interface.
| Interface | Common Peripheral | Purpose |
|---|---|---|
| USB | Keyboard, mouse, flash drive, printer | Peripheral connectivity and data transfer |
| HDMI | Monitor, projector | Digital audio/video transmission |
| Ethernet | Network adapter, computer | Wired networking |
| Audio Jack | Headphones, speakers, microphone | Audio input/output |
| Bluetooth | Wireless mouse, keyboard, headphones | Short-range wireless communication |
| Wi-Fi | Wireless network adapter | Wireless network communication |
24. Wired and Wireless Peripherals
| Wired | Wireless |
|---|---|
| Uses a physical cable. | Uses radio or another wireless communication method. |
| Generally requires physical connection to the host. | Provides greater freedom of movement. |
| Examples: USB keyboard, Ethernet adapter. | Examples: Bluetooth mouse, Wi-Fi adapter. |
25. Choosing the Right Peripheral
The most appropriate peripheral depends on the task and the requirements of the user.
| Requirement | Suitable Peripheral |
|---|---|
| Type a document | Keyboard |
| Select objects on screen | Mouse or touchpad |
| Digitise a paper document | Scanner |
| Attend an online class | Webcam + microphone + speakers/headphones |
| Print many documents quickly | Laser printer |
| Store files for transport | USB flash drive or external SSD |
| Display content to a large audience | Projector or large display |
| Connect to a wired network | Ethernet adapter |
26. Peripheral Devices in a Computer Lab
A typical school computer lab may use many peripheral devices.
| Peripheral | Purpose in the Lab |
|---|---|
| Keyboard | Typing and programming. |
| Mouse | Graphical interaction. |
| Monitor | Visual output. |
| Printer | Printing assignments and documents. |
| Projector | Teacher demonstrations and presentations. |
| Speakers | Audio and multimedia. |
| Webcam | Video communication. |
| Network Adapter | Connecting computers to the school network. |
| External Storage | Backup and transfer of files. |
27. Care and Maintenance of Peripheral Devices
- Keep devices clean and dry.
- Handle connectors carefully.
- Do not force plugs into ports.
- Keep liquids away from electronic equipment.
- Use appropriate power protection where required.
- Store portable devices safely.
- Use compatible cables and adapters.
- Keep device drivers and system software appropriately updated.
- Safely eject removable storage when the operating system requires it.
28. Peripheral Devices and Accessibility
Specialised or adapted peripherals can help people interact with computers according to their individual needs.
| Technology | Possible Use |
|---|---|
| Large-key keyboard | Helps users who find small keys difficult to operate. |
| Alternative pointing device | Provides another way to control the pointer. |
| Microphone + speech recognition | Supports voice-based computer interaction. |
| Screen reader-compatible controls | Helps users access information through speech or Braille output. |
| Braille display | Provides refreshable tactile output for compatible digital content. |
29. Input vs Output Peripherals
| Input Peripheral | Output Peripheral |
|---|---|
| Provides data or commands to the computer. | Presents information produced by the computer. |
| Usually communicates data toward the computer. | Usually communicates information toward the user or another system. |
| Keyboard, mouse, scanner, microphone. | Monitor, printer, speakers, projector. |
30. Internal Components vs Peripheral Devices
| Internal Components | Peripheral Devices |
|---|---|
| Usually form part of the main computer system. | Extend the computer's input, output, storage or communication capabilities. |
| CPU, RAM, motherboard. | Keyboard, mouse, monitor, printer. |
| Often located inside the system enclosure. | Often external, although some peripheral devices may be internally installed or integrated. |
31. Case Study: School Presentation
Situation
A teacher wants to conduct a multimedia presentation. The teacher has a laptop, projector, speakers, microphone and wireless presentation controller.
Questions
- Which device provides visual output to the class?
- Which device provides audio output?
- Which device captures the teacher's voice?
- Which device can be used to control the presentation?
- Classify these devices as input or output peripherals.
Suggested Answers
- Projector.
- Speakers.
- Microphone.
- Wireless presentation controller.
- Projector and speakers are output devices. The microphone and presentation controller provide input.
32. Competency-Based Questions
Question 1
Deepak wants to transfer photographs from one computer to another without using the Internet. Which peripheral could he use?
Answer: He could use a USB flash drive or an external SSD to copy and transfer the photographs.
Question 2
A supermarket uses a device to read the black-and-white pattern printed on products during billing. Identify the peripheral.
Answer: A barcode scanner is used to read the product's barcode and provide the encoded information to the billing system.
Question 3
A teacher needs to conduct an online class. Which peripheral devices would help the teacher communicate with students?
Answer: A webcam can capture video, a microphone can capture the teacher's voice, and speakers or headphones can provide audio output.
Question 4
Riya wants to convert a printed photograph into a digital image that can be edited on a computer. Which device should she use?
Answer: She should use a scanner, which captures the physical photograph and converts it into digital data.
Question 5
An office needs to produce 100 high-quality copies of an important circular quickly. Which printer would generally be appropriate?
Answer: A laser printer would generally be suitable because it is designed for fast, high-volume document printing and produces sharp text.
33. Classroom Activity: Peripheral Hunt 🔎
Observe the computer lab and identify as many peripheral devices as possible.
| Peripheral | Category | Input / Output / Both | Function |
|---|---|---|---|
| ________________ | ________________ | ________________ | ________________ |
| ________________ | ________________ | ________________ | ________________ |
| ________________ | ________________ | ________________ | ________________ |
| ________________ | ________________ | ________________ | ________________ |
| ________________ | ________________ | ________________ | ________________ |
34. Classroom Activity: Choose the Right Device
| Situation | Best Peripheral | Reason |
|---|---|---|
| Type a Python program | ________________ | ________________ |
| Digitise a paper document | ________________ | ________________ |
| Give a classroom presentation | ________________ | ________________ |
| Store a backup externally | ________________ | ________________ |
| Attend a video conference | ________________ | ________________ |
35. Think About It 🤔
- What is a peripheral device?
- Why are peripheral devices important?
- What is the difference between input and output peripherals?
- Name five input peripherals.
- Name five output peripherals.
- Why is a touchscreen considered both an input and output device?
- What is the purpose of a device driver?
- What is the difference between wired and wireless peripherals?
- Why is a scanner an input device?
- Why is a printer an output device?
- What is a storage peripheral?
- How can peripheral devices improve accessibility?
36. Key Terms
| Term | Meaning |
|---|---|
| Peripheral Device | Hardware connected to a computer to provide additional input, output, storage or communication functionality. |
| Input Device | Device used to enter data or instructions into a computer. |
| Output Device | Device used to present computer-generated information. |
| Storage Device | Device used to store data persistently or provide additional storage. |
| Communication Device | Device that enables data exchange between computers or networks. |
| Device Driver | Software that allows an operating system to communicate with a hardware device. |
| USB | Universal Serial Bus, a standard interface for connecting many peripherals. |
| Scanner | Input device that converts physical documents or images into digital data. |
| Printer | Output device that produces physical copies of digital content. |
| Touchscreen | Device that combines visual output with touch-based input. |
37. Lesson Recap
- A peripheral device extends the functionality of a computer system.
- Peripherals can be classified as input, output, storage, communication and input/output devices.
- A keyboard, mouse, scanner, microphone and webcam are examples of input peripherals.
- A monitor, printer, speakers and projector are examples of output peripherals.
- USB flash drives and external SSDs are examples of storage peripherals.
- Network and wireless adapters can provide communication capabilities.
- A touchscreen can perform both input and output functions.
- Device drivers help the operating system communicate with hardware devices.
- Peripheral devices may use wired or wireless interfaces.
- The correct peripheral should be selected according to the task, compatibility, performance, accessibility and other requirements.
38. Homework 📝
- Define a peripheral device.
- Explain any four categories of peripheral devices.
- List five input peripheral devices and explain their functions.
- List five output peripheral devices and explain their functions.
- What are storage peripherals? Give three examples.
- What are communication peripherals? Give three examples.
- Why is a touchscreen considered both an input and output device?
- What is a device driver?
- Differentiate between wired and wireless peripherals.
- Explain the importance of peripheral devices in a school computer laboratory.
39. Quick Assessment
- What is a peripheral device?
- Name two input peripherals.
- Name two output peripherals.
- Name two storage peripherals.
- Name two communication peripherals.
- What is the function of a scanner?
- What is the function of a printer?
- What is the purpose of a webcam?
- Why is a touchscreen an input/output device?
- What does USB stand for?
- What is a device driver?
- Give one example of a wireless peripheral.
- Give one example of an impact printer.
- Give one example of a non-impact printer.
- Why are peripheral devices important in a computer system?