Num Lock is a function that activates the numeric keypad on a computer keyboard. Synonyms for Num Lock include Number Lock, Numeric Lock, Numpad Lock, Numeric Keypad Lock, and Number Pad Lock. These terms refer to the same function, which allows users to enter numbers quickly and easily. Some keyboards have a light that indicates when Num Lock is on, while others may emit a beep or other sound to confirm that the function is activated. Regardless of the term used to describe Num Lock, the function itself is an important tool for anyone who frequently needs to enter numeric data into a computer.