A keypad is a set of keys or buttons arranged in a specific layout, used for inputting data or commands into electronic devices. Commonly found on devices like telephones, computers, and security systems, keypads can be mechanical or touch-sensitive. They often feature numbers, letters, and symbols, allowing users to enter information easily. Keypads come in various forms, including numeric keypads, which typically have 0-9 and additional function keys, and alphanumeric keypads, which include letters as well. Some keypads are designed for specific applications, such as ATM machines or point-of-sale systems, enhancing user interaction and accessibility.