Ins key on computer keyboard is Insert key (abbreviated as INS), which is a key of computer keyboard and is mainly used to switch text input modes in word processor.

Its function:

One is the overwrite mode, where the new input word at the cursor position will replace the original word.

The second mode is insertion, in which a newly entered word is inserted at the cursor position, and the original word moves backward accordingly.

In early computer terminals, if you were in overlay mode, the cursor would become a square instead of the usual vertical line.