A manual is a musical keyboard designed to be played with the hands, on an instrument such as a pipe organ, harpsichord, clavichord, electronic organ, melodica, or synthesizer. The term "manual" is used with regard to any hand keyboard on these instruments to distinguish it from the pedalboard, which is a keyboard that the organist plays with their feet. It is proper to use "manual" rather than "keyboard", then, when referring to the hand keyboards on any instrument that has a pedalboard.

A musical keyboard is the set of adjacent depressible levers or keys on a musical instrument. Keyboards typically contain keys for playing the twelve notes of the Western musical scale, with a combination of larger, longer keys and smaller, shorter keys that repeats at the interval of an octave. Pressing a key on the keyboard makes the instrument produce sounds—either by mechanically striking a string or tine, plucking a string (harpsichord), causing air to flow through a pipe organ, striking a bell (carillon), or activating an electronic circuit. Since the most commonly encountered keyboard instrument is the piano, the keyboard layout is often referred to as the piano keyboard or simply piano keys.