Input device

1. Text input devices
   1. Keyboard - a device to input text and characters by depressing buttons (referred to as keys or buttons).
2. Pointing devices
   1. Mouse - a pointing device that detects two dimensional motion relative to its supporting surface.
      1. Optical Mouse - uses light (laser technology) to determine mouse motion.
   2. Trackball - a pointing device consisting of an exposed protruding ball housed in a socket that detects rotation about two axes.
   3. Touchscreen - senses the user pressing directly on the monitor.
3. Gaming devices
   1. Joystick - a hand-operated pivoted stick whose position is transmitted to the computer.
   2. Game pad - a hand held game controller that relies on the digits (especially thumbs) to provide input.
   3. Game controller - a specific type of controller specialized for certain gaming purposes.
4. Image, Video input devices
   1. Image scanner - a device that provides input by analyzing images, printed text, handwriting, or an object.
   2. Web cam - a video camera used to provide visual input that can be easily transferred over the internet.
5. Audio input devices
   1. Microphone - an acoustic sensor that provides input by converting sound into electrical signals.