Unit 3.7
Input and Output Devices of a Computer
IT 231: IT and Application
Learning Objectives 🎯
By the end of this chapter, you will be able to:
- ✅ Differentiate between an input device and an output device.
- ✅ Identify common types of input devices.
- ✅ Identify common types of output devices.
The Human-Computer Bridge
Input and Output (I/O) devices are the peripherals that allow us to interact with a computer.
Input Devices ➡️
Send data and instructions TO the computer.
(You talking to the computer)
⬅️ Output Devices
Receive feedback and results FROM the computer.
(The computer talking to you)
Input Devices: Sending Data IN
Definition: Input devices translate our real-world actions (like keystrokes, movements, and sounds) into digital data that the computer can process.
Human Action 🚶 → Input Device ⌨️ → Digital Data 💻
Common Input Devices ⌨️🖱️
Keyboard
The most common input device for typing text and executing commands.
Mouse
A pointing device used to control the on-screen cursor and interact with the GUI.
Microphone 🎙️
Captures audio and converts it into a digital format for recording or voice commands.
Scanner 📄
Converts physical documents, photos, or drawings into digital image files.
Output Devices: Getting Feedback OUT
Definition: Output devices translate the computer's processed digital data back into a form that humans can see, hear, or touch.
Digital Data 💻 → Output Device 🖥️ → Human Perception 👀
Common Output Devices 🖥️🖨️
Monitor (Display)
The primary output device, displaying text, graphics, and video.
Printer
Produces a physical "hard copy" of digital text and images on paper.
Speakers / Headphones 🎧
Produce audio output, from system sounds to music and voice.
Projector 📽️
Displays the computer's screen output onto a larger surface for presentations or viewing.
Input, Output, or Both? The Touchscreen 🤔
Discussion Point: Is a smartphone screen an input or output device?
- As an Input Device: You provide input by tapping icons, swiping between screens, and typing on the virtual keyboard.
- As an Output Device: It displays the user interface, videos, images, and text from the phone's processor.
Conclusion: It's both! A touchscreen is a classic example of a hybrid I/O device.
I/O Devices in Nepal 🇳🇵
Let's look at some practical examples you might see every day.
Input in Nepal
- QR Code Scanners: Essential for digital payments via eSewa, Khalti, and Fonepay at local shops.
- Biometric Scanners: Used for the National ID card system and at some government offices for attendance.
Output in Nepal
- Digital Notice Boards: Displaying information at universities, hospitals, and public transport hubs in Kathmandu.
- Printers: Crucial in every "karyalaya" (office) for printing official documents, letters ("patra"), and reports.
Key Takeaways 🔑
- Input devices send data TO the computer. (e.g., Keyboard, Mouse)
- Output devices receive data FROM the computer. (e.g., Monitor, Printer)
- These devices form the essential bridge between humans and machines.
- Some devices, like touchscreens, can be both input and output.