In basketball, a violation is the most minor class of illegal action. Most violations are committed by the team with possession of the ball, when a player mishandles the ball or makes an illegal move. The typical penalty for a violation is loss of the ball to the other team. This is one type of turnover.
Stepping out of bounds and throwing the ball out of bounds may also be considered violations that result in loss of the ball.
Acts involving contact between opponents or unsportsmanlike conduct are called fouls, usually a personal foul.