A computer keyboard is a peripheral input device modeled after the typewriter keyboard which uses an arrangement of buttons or keys to act as mechanical levers or electronic switches. Replacing early punched cards and paper tape technology, interaction via teleprinter-style keyboards have been the main input method for computers since the 1970s, supplemented by the computer mouse since the 1980s.
A wired computer keyboard for desktop use manufactured by Lenovo
Keyboards on laptops usually have a shorter travel distance and a reduced set of keys.
Multifunction keyboard with LCD function keys
A Greek keyboard lets the user type in both Greek and the Latin alphabet (MacBook Pro).
A push-button or simply button is a simple switch mechanism to control some aspect of a machine or a process. Buttons are typically made out of hard material, usually plastic or metal. The surface is usually flat or shaped to accommodate the human finger or hand, so as to be easily depressed or pushed. Buttons are most often biased switches, although many un-biased buttons still require a spring to return to their un-pushed state.
Generic arcade game buttons
Buttons on a handheld calculator.
Button shaped as an octagon.