The space bar, spacebar, or space key, 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. Users typically only use their right thumb to press it. It is large enough so that a thumb from either hand can use it easily.
In computer games and other applications the key has myriad uses in addition to its normal purpose in typing, such as jumping and adding marks to check boxes.
In certain programs for playback of digital video, the space bar is used for pausing and resuming the playback.
The space bar is the biggest key on the keyboard, and is typically the most used key on the keyboard.