A divertimento is a piece of music which is lighthearted and easy to listen to. It is often performed on social occasions, e.g. as music to be played while people eat, or as after-dinner music.
The divertimento became popular in the 18th century. They were played by a small group of instruments. Mozart wrote several pieces called "divertimento". They are similar to a serenade. A divertimento often has several movements, e.g. six, seven or more.
There are a few examples from the 20th century of pieces called "divertimento", e.g. works by including works by Ferruccio Busoni, Béla Bartók, and Igor Stravinsky (from his ballet Le Baiser de la Fée).