Illegal use of hands in basketball refers to when a player slaps or otherwise commits a foul with their hands against the opposing player. This can happen on offense if a ball handler uses their free hand to push off a defender or on defense if they are trying to stop an offensive player from shooting, passing, or dribbling.
Basketball is supposed to be a low to non-contact sport, since no player is supposed to touch any other player on the court in a purposeful or harmful manner. So, when a player uses his or her hands to stop a play or move toward the basket and past a defender, a foul is called. Here are some examples of illegal uses of hands:
Any of these situations occurring would call for a referee to blow the whistle and call a personal foul on the perpetrator. They can be difficult to avoid, however, because a player's hands are constantly working to prevent an offensive player from scoring or to get past a defender and score 2 or more points.