Q.What are input and output devices? Explain any four input devices and any four output devices, and distinguish between soft copy and hard copy.

Input devices bring data into the computer and output devices give results out; the answer should define both, give four examples of each, and explain soft versus hard copy.

Input devices. As Section d explains, an input device is any hardware used to feed data and instructions into the computer, converting human information into the electronic form the computer can process. Four common input devices are:

1. Keyboard — the most common input device, used to type letters, numbers, symbols, and commands.
2. Mouse — a pointing device that moves a pointer on the screen and lets the user select, click, and drag items.
3. Scanner — reads a printed page or photograph and converts it into a digital image stored in the computer.
4. Microphone — takes in sound (voice or music) and converts it into digital form, for recording or voice commands.

(Other examples include the webcam, joystick, barcode reader, and OMR/OCR/MICR readers.)

Output devices. As Section e explains, an output device is any hardware that gives out the results produced by the computer, converting the computer's signals into a form a human can see, hear, or hold. Four common output devices are:

1. Monitor (VDU) — displays text, pictures, and video on a screen as soft-copy output.
2. Printer — produces printed hard-copy output on paper (for example, dot-matrix, inkjet, and laser printers).
3. Speakers / headphones — give out sound output such as music and speech.
4. Plotter — draws high-quality line diagrams, maps, and engineering drawings on large paper.

(Another example is the projector, which throws the display onto a large screen.) …

Do not mix input and output devices — for example, listing a printer as an input device or a scanner as an output device. Use the direction test. For soft vs hard copy, remember: s …