GeezerVison

Backspace (← Backspace, ⌫) is the keyboard key that in typewriters originally pushed the carriage one position backwards. In modern computer systems, it typically moves the display cursor one position backwards,^[a] deletes the character at that position, and shifts back any text after^[b] that position by one character.

Although the term "backspace" is the traditional name of the key which steps the carriage back and/or^[c] deletes the previous character, the actual key may be labeled in a variety of ways—for example delete,^[1] erase,^[d] or with a left pointing arrow.^[3] Some very early typewriters labeled this key the backspacer key. A dedicated symbol for "backspace" exists as U+232B ⌫ ERASE TO THE LEFT but its use as a keyboard label is not universal.

Backspace is distinct from the delete key, which in a teletypewriter would punch out all the holes in punched paper tape to strike out a character, and in modern computers deletes text at or following the cursor position. Also, the delete key often works as a generic command to remove an object (such as an image inside a document, or a file in a file manager), while backspace usually does not.^[4][5] Full-size Mac keyboards in the USA have two keys labeled delete; a key that functions as a backspace key and a key that functions as a delete key, while in the UK, the backspace key has a left-pointing arrow on it instead.^[6] Smaller Mac keyboards, such as laptop keyboards, have only a key that functions as a backspace key.^[7] Full-size PC keyboards have a backspace key (in the main section) and two delete keys (in the extended area).

With some typewriters,^[e] a typist would, for example, type a lowercase letter A with acute accent (á) by typing a lowercase letter A, backspace, and then the acute accent key. This technique (also known as overstrike) is the basis for such spacing modifiers in computer character sets such as the ASCII caret (^, for the circumflex accent). Backspace composition no longer works with typical modern digital displays or typesetting systems.^[f] It has to some degree been replaced with the combining diacritical marks mechanism of Unicode, though such characters do not work well with many computer fonts, and precomposed characters continue to be used. (Some software like TeX or Microsoft Windows use the opposite method to apply a diacritical mark, namely typing the accent first, and then the base letter to be accented.)