overwrite modeMost word processors and text editors allow you to choose between two modes: overwrite and insert. In overwrite mode, every character you type is displayed at the cursor position. If a character is already at that position, it is replaced. In insert mode, each character you type is inserted at the cursor position. This means that existing characters are moved over to make room for the new character, but they are not replaced.
Overwrite mode is sometimes called overtype mode.