A keypad is an input device that is used to enter numerical or alphanumeric data into a computer, calculator, or other electronic device. It consists of a set of buttons or keys, typically arranged in a grid or matrix pattern, that are labeled with numbers, letters, symbols, or functions. Key pads can be found on many electronic devices, such as telephones, calculators, remote controls, and security systems. They are often used to enter PIN codes, phone numbers, passwords, and other types of data. Some key pads also have additional features, such as backlighting or touch-sensitive buttons.