Input Devices

Definition:
Input devices are hardware components that allow users to enter data or commands into a computer system. They serve as the bridge between the user and the computer, enabling interaction and data collection.

Common Examples and Uses:

Input Device	Typical Use Case
Keyboard	Entering text, commands, and data
Numeric Keypad	Inputting numbers quickly, e.g., ATMS, calculators
Mouse	Navigating GUIs, selecting, dragging, and dropping
Touchpad/Trackpad	Laptop navigation
Tracker Ball	Alternative pointing device, useful for accessibility
Joystick/Driving Wheel	Navigating GUIS, selecting, dragging, and dropping
Touch Screen	Smartphones, tablets, kiosks
Graphics Tablet	Digital drawing and design
Scanner (2D/3D)	Digitising documents, images, and objects
Digital Camera/Webcam	Capturing photos and videos
Microphone	Recording audio, voice commands
Sensors	Measuring temperature, light, humidity, etc.
Magnetic Stripe Reader	Reading bank cards, ID cards
Chip and PIN Reader	Secure payment transactions
Barcode/QR Code Reader	Retail, inventory management
OMR/OCR	Automated exam marking, digitizing printed text
Light Pen	Drawing directly on screens
Automated exam marking, digitising printed text	Operating devices from a distance

Special Considerations:

• Accessibility: Devices like microphones, touchscreens, and eye trackers enable users with physical disabilities to interact with computers.
• Direct Data Entry: Devices such as barcode readers, OMR, and OCR automate data input, reducing human error and increasing efficiency.
• Analogue Inputs: Sensors and microphones often require an Analogue-to-Digital Converter (ADC) to translate real-world signals into digital data that the computer can process.

Output Devices

Definition:
Output devices are hardware components that receive processed data from a computer and present it in a form understandable to the user, such as visual, audio, or physical output.

Common Examples and Uses:

Output Device	Typical Use Case
Monitor (CRT, TFT)	Displaying text, images, videos
Multimedia Projector	Enlarging computer display for presentations
Printer (Laser, Inkjet, Dot Matrix)	Producing hard copies of documents, photos
Plotter	Printing large-scale graphics, architectural blueprints
3D Printer	Creating physical models from digital designs
Speaker	Outputting sound, music, alerts
Actuator (Motor, Buzzer, Light, Heater)	Controlling machines and environments
Touch Screen	Can serve as both input and output device

Special Considerations:

• Suitability: The choice of output device depends on the required output format (e.g., visual, audio, physical).
• Control Devices: Actuators are used in automated systems to perform real-world actions, such as opening doors or switching on lights.
• Accessibility: Speakers and screen readers assist visually impaired users by converting text to speech.

Key Differences and Relationships

Feature	Input Devices	Output Devices
Function	Send data/commands to the computer	Communicate processed data to the user
Direction of Data	User → Computer	Computer → User
Examples	Keyboard, mouse, scanner, microphone	Monitor, printer, speaker, actuator