Space bar - Definition

A computer keyboard

Space bar is a key on an alphanumeric keyboard in the form of a horizontal bar in the lowermost row, significantly wider than other keys. Its main purpose is to conveniently enter the space, e.g., between words during typing.

Depending on the operating system, the space bar used with a modifier key such as the control key may have functions such as resizing or closing the current window.

In computer games and other applications the key has myriad uses in addition to its normal purpose in typing.