Mouse button

One-button mouse
Three-button mouse
Five-button ergonomic mouse

A mouse button is an electric switch on a computer mouse which can be pressed (“clicked”) to select or interact with an element of a graphical user interface. Mouse buttons are most commonly implemented as miniature snap-action switches (micro switches).

The three-button scrollmouse has become the most commonly available design. Users most commonly employ the second button to invoke a contextual menu in the computer's software user interface, which contains options specifically tailored to the interface element over which the pointer currently sits. By default, the primary mouse button sits located on the left-hand side of the mouse, for the benefit of right-handed users; left-handed users can usually reverse this configuration via software.