Keyboards are and always have been the de facto method of computer input. A common keyboard uses slightly over 100 keys that the user presses to feed commands or data to a computer. Keyboards are the basis of computer input, and many computers will not even boot unless a keyboard is installed.

In terms of computer history, computer mice are a fairly new concept. The mouse opened up doors to many potential computer users as it made computing faster and easier. Instead of the user being required to enter long and confusing commands, the user could point to an icon and execute the same command much faster. Mice sparked the next wave of software, the Graphical User Interface. Despite the mouse's ease of use, it will never replace the functionality of a keyboard.

Technically, a joystick is not all that different from a keyboard. A joystick, or a gamepad, takes input through a D-pad and various buttons. A joystick is really a keyboard with fewer buttons that is ergonomically constructed to allow comfort and ease of use during gameplay.

A scanner is a device that allows hard copy documents to be transformed into files that can be used elsewhere on a computer. The most common type of scanner is the flatbed scanner. A scanner works by using a CCD array, a collection of small light-sensitive diodes, that converts photons into electrons. This array of electrons is then turned into digitized data that the computer can understand.

A microphone is a tool used to send analog audio to a sound card so that it can be transformed into digital audio.