What Does Backspace (BKSP) Mean?

The backspace key is a key found on most keyboards, typewriters and virtual keyboard interfaces. The backspace key originated on the typewriter. In modern computer systems, backspace deletes the character to the left of the cursor and shifts all text after that point by one position.

Techopedia Explains Backspace (BKSP)

Nearly all models of manual typewriters as well as modern keyboards have the backspace key. The backspace key is denoted on keyboards by an arrow that points to the left, and it is often located at the top-right portion of the keyboard. In typewriters, the backspace key reverses the platen carriage by one character space with each stroke.