Corps de ballet
The corps de ballet are a group of dancers in a ballet company who are not soloists. They perform as a group (the Flowers in the "Waltz of the Flowers" from The Nutcracker, for example) and at other times as a backdrop for the soloists (the peasants in the mad scene from Giselle).
Corps De Ballet Media
In this scene from Swan Lake, the corps de ballet is forming a "V" at the front of the stage. They are directing attention to the principal dancer in the spotlight. The dancers behind her are also corps de ballet and form a backdrop.