Space bar

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. It is large enough so that a thumb from either hand can use it. The space bar key is almost always found on the bottom row of standard QWERTY or Dvorak keyboard layouts. Although it varies by Operating System, the space bar usually lies between the Alt (Windows) or Command (Mac) keys.

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, half-spacing, or even backspacing. On web browsers, the space bar usually allows the user to scroll down or to scroll up when the space bar is used with the shift key.

In many programs for playback of linear media, the space bar is used for pausing and resuming playback, or for manually advancing through text.