Insert Key

The Insert key (often abbreviated INS) is a key commonly found on computer keyboards.

It is primarily used to switch between the two text-entering modes on a personal computer (PC) or word processor. The first is overtype mode, in which the cursor, when typing, overwrites any text that is present on and after its current location. The other is insert mode, where the cursor inserts a character at its current position, forcing all characters past it one position further. The insert/overtype mode toggling is not global for the computer or even for a single application but rather local to the text input window in which the Insert key was pressed.

On early text-based computing environments and terminals, when the cursor was in overtype mode, it was represented as a block that surrounded the entire letter to be overstruck; when in insert mode, the cursor consisted of the vertical bar that is highly common among modern applications, or a blinking underline under the position where a new character would be inserted.

Overtype mode can also be referred to as overscript mode, and is sometimes erroneously referred to as overstrike mode, which is a typography term.

Notably, on some recent keyboards, the Insert key is completely absent (except on the numeric keypad), its space instead filled with a double-size Delete key.