A piano is a type of musical instrument classified as a keyboard instrument. It produces sound by striking strings with hammers when the keys are pressed. Pianos come in two main types: grand and upright, both of which vary in size and sound quality. The versatility of the piano allows it to be used in various musical genres, including classical, jazz, pop, and more. Pianists can create a wide range of tones and dynamics, making the piano an expressive instrument ideal for both solo performances and accompanying other players or singers.