The numeric keypad is a section of the keyboard usually located on the right part, which allows, according to the activated mode, to enter the digits and the decimal separator, or to control the cursor and the insertion of characters. It also contains the signs of operations, as well as a validation key.
This is the Num Lock key that allows you to switch the keypad from one mode to another; when in numeric entry mode, this is usually indicated by a light-emitting diode that stays on.
It is normally used with a mini-keyboard that does not have a built-in keypad.