What does ritornello mean in music?

A ritornello is a musical section that recurs throughout a composition, usually at the end of each section or verse. It is often played by the full ensemble and is often used as a way to unify a piece of music. The term ritornello is derived from the Italian word "ritornare", which means "to return". In music, the ritornello typically returns to the same musical material, although it may be varied slightly each time it is repeated. Ritornellos are often used in instrumental music, but they can also be found in vocal music, such as operas and cantatas.