what is a sonata? how is it related to the sonata form?
A sonata is a three movement piece of music, typically for one instrument with piano accompaniment, or just piano. Although they can be fore multiple instruments. Sonata form is a structure for a musical movement used not only in sonatas, but also in symphonies and concertos. The second movement of a sonata is usually a minuet or scherzo, and the third is commonly a rondo.
Sonata form (also sonata-allegro form or first movement form) is a large-scale musical structure used widely since the middle of the 18th century (the early Classical period).