What is "pedal piano"

The pedal piano (or piano-pédalier or pédalier, French piano-pédalier, Italian piano-pédalier (uses the French word), Spanish piano con pedales, Catalan piano amb pedals, German Pedalflügel, Russian педальное фортепиано, Japanese ペダル・ピアノ) is a kind of piano that includes a pedalboard, enabling bass register notes to be played with the feet, as is standard on the organ.

There are two broad types of pedal pianos: either the pedal board may be an integral part of the instrument, using the same strings and mechanism as the manual keyboard (e.g. the 19th century Érard pedal grand piano and Pleyel upright pedal piano), or it may consist of two independent pianos (each with its separate mechanics and strings) which are placed one above the other, either a regular piano played by the hands and a bass-register piano played by the feet (e.g. the 18th century pedal piano owned by Wolfgang Amadeus Mozart and the 21st century Doppio Borgato), or two standard pianos of which the lower one is played from a pedalboard which acts on its (manual) keyboard through a special mechanism (e.g. the 21st century Pinchi Pedalpiano System).