A computer key is a small button on a keyboard that performs a specific function when pressed. Each key corresponds to a letter, number, or command, allowing users to input data and control their computer. Common keys include letters A-Z, numbers 0-9, and special function keys like Enter and Escape. Keys are typically made of plastic and are arranged in a standard layout known as QWERTY. This layout helps users type efficiently. Some keyboards also feature additional keys for multimedia functions, such as adjusting volume or playing music, enhancing the overall user experience.