Alternatively referred to as space and the space key, the spacebar or space bar is a long horizontal on the lower edge of a . It is always the largest and longest key on the keyboard. When the spacebar key is pressed, it creates an empty space, also known as a space character or that helps separate words and other characters in a sentences. For example, if there were not spaces in this paragraph, all of the text would be together and very difficult to read.. The space bar, spacebar, blank, or space key is a key on a typewriter or 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 a space , e.g., between words during typing .. The space-cadet keyboard is a keyboard used on MIT Lisp machines and designed [when?] by John L. Kulp, which inspired several still-current jargon terms in the field of computer science and influenced the design of Emacs..