A new genre developed at the end of the Baroque Period called the sonata.
If a concerto can be thought of as an operatic aria with an instrument instead of a singer, a sonata can be thought of as a concerto with a piano (or harp, harpsichord, or some other chord-capable instrument) instead of an orchestra. Sonatas have three movements, usually in a fast - slow - fast pattern, like concerti.
A piece for solo piano composed during this period is also called a sonata.