Diagram showing input devices, output devices and input/output devices of a computer
A keyboard is an input device. It sends data (the keys you press) to the computer. It does not show you results, so it is not an output device.
The same simple rule works for almost every device: if it sends information into the computer, it is an input device. If it shows or plays information from the computer, it is an output device. Some devices do both.
What Is an Input Device?
An input device lets you give data, commands or instructions to a computer. The computer then processes that data and produces a result. Common input devices are:
- Keyboard: types letters, numbers and commands.
- Mouse: moves the pointer and selects items.
- Scanner: converts paper documents or photos into digital files.
- Microphone: records sound and voice.
- Webcam: captures video and images.
- Joystick and gamepad: control games.
- Barcode reader: reads product codes in shops.
What Is an Output Device?
An output device shows or plays the result after the computer has processed your data. Common output devices are:
- Monitor: displays text, images and video.
- Printer: puts text or images on paper.
- Speakers and headphones: play sound.
- Projector: shows the screen on a wall or large screen.
- Plotter: prints large drawings and maps.
What Are Input/Output (I/O) Devices?
Some devices can both send data to the computer and receive data from it. These are called input/output devices.
- Touchscreen: you touch it (input) and it displays the result (output).
- Headset: the microphone is input and the earphones are output.
- USB flash drive and external hard drive: you can save files to them and read files from them.
- Network card or modem: sends and receives data over the internet.
Input vs Output vs I/O Devices: Quick Table
| Device | Type | Why |
|---|---|---|
| Keyboard | Input | Sends typed data to the computer |
| Mouse | Input | Sends pointer movement and clicks |
| Scanner | Input | Sends a digital copy of a page |
| Microphone | Input | Sends sound |
| Monitor | Output | Shows results on screen |
| Printer | Output | Prints results on paper |
| Speakers | Output | Play sound |
| Touchscreen | Input and output | Accepts touch and displays results |
| Headset | Input and output | Microphone in, sound out |
| USB drive | Input and output | Files can be saved and read |
Frequently Asked Questions
Is a keyboard an input or output device?
A keyboard is an input device. Pressing a key sends a signal to the computer. The small lights for Caps Lock or Num Lock only show the keyboard's own status, so the keyboard is still classified as an input device.
Is a mouse an input or output device?
A mouse is an input device because it sends pointer movement and clicks to the computer.
Is a monitor an input or output device?
A normal monitor is an output device. A touchscreen monitor is both input and output.
Is a printer an input or output device?
A printer is an output device. A multifunction printer that also has a scanner works as both an input and an output device.
What is the difference between input and output devices?
Input devices send data to the computer. Output devices receive the processed result from the computer and show or play it for you.
Is a USB flash drive an input or output device?
It is an input/output device, because it can both give files to the computer and receive files from it. It is also called a storage device.
Quick Summary
Keyboard, mouse, scanner and microphone are input devices. Monitor, printer and speakers are output devices. Touchscreens, headsets and USB drives work as both. If you are ever unsure, ask one question: does this device send data to the computer, or show data from the computer?
