Volleyball is an Olympic team sport in which two teams of six active players, separated by a high net, each try to score points against one another by grounding a ball on the other team's court under organized rules.

The complete rules of volleyball are extensive, but in general, play proceeds as follows. Points are scored by grounding the ball on the opponents' court, or when the opponent commits a fault. The first team to reach 25 points wins the set and the first team to win three sets wins the match. Teams can contact the ball no more than three times before the ball crosses the net, and consecutive contacts must be made by different players. The ball is usually played with the hands or arms, but players can legally strike or push (short contact) the ball with any part of the body.

Through time, volleyball has developed to involve common techniques of spiking, passing, blocking, and setting, as well as specialised player positions and offensive and defensive structures. Because many plays are made above the top of the net, vertical jumping is an athletic skill emphasised in volleyball. This article focuses on competitive indoor volleyball, which is carefully regulated and played indoors. Numerous variations of volleyball have developed for casual play, as has the Olympic spin-off sport beach volleyball.