Why piano called keyboard instrument?

The piano is called a keyboard instrument because it produces sound by means of a keyboard, which consists of a set of black and white keys that are played by pressing them with the fingers. When a key is pressed, it causes a corresponding hammer to strike a string, which causes the string to vibrate and produce sound. The pitch of the sound produced depends on the length and tension of the string, and the timbre of the sound depends on the material of the string and the shape of the piano's soundboard. The piano is a member of the keyboard family of instruments, which also includes the harpsichord, the clavichord, and the organ.