A computer input device is anything that sends data to the computer. The first input devices were punch cards and later keyboards. They now include mice, Web cams and digital cameras.
The keyboard is the most commonly known input device. Keyboards are usually modeled after a typewriter; however, they now include thumb-sized keyboards for cell phones and numeric keyboards similar to a calculator.
A computer mouse sends input to the computer by detecting two-dimensional motion. This type of input device includes the scroll wheel mouse, laser mouse, track balls and digital pens.
Video Input Devices
A video input device sends image data to the computer. Video input devices include digital cameras, scanners, Web cams and bar code readers.
Audio Input Devices
Audio input devices capture sound and send it to the computer. The most common audio input device is the microphone, but there are also MIDI keyboards and digital instruments.
Touchscreens are used by touching the display area with either a finger or stylus. They can be found on PDAs, mobile phones, video games and tablet PCs.