One of the things it could be is a mode of word processors. In TYPEOVER mode, instead of INSERTing text where the insertions point is causing subsequent characters to move to the right, each character that is typed REPLACES an existing character. In MS Word and LibreOffice this is toggled by a press of the <Insert> key (often found between the letter portion of the keyboard and the Numpad).
In LibreOffice, when Typeover is active, the character that will be replaced blinks in reverse graphics (white letter in black rectangle).
You have to hit the insert button on your keyboard.
Typeover
typeover
To enable typeover mode (also known as overwrite mode) on a Mac, you typically need to press the "Insert" key, which is not present on most Mac keyboards. Instead, you can use the "fn" + "Return" keys in some applications to toggle between insert and overwrite modes. In text editing applications, you can also check the settings or preferences for options related to typing modes. If your specific application does not support overwrite mode, you may need to look for third-party text editors that do.
Press backspace, it's above the Enter key. A. Backspace key once B. Delete key once C. Insert key to toggle into typeover mode then press the spacebar once D. Spacebar once then the delete key I think its A The answer is ( B) I did the test.
The most common implementation of such a thing is usually called a clipboard.