A turnover in basketball is whenever a team loses possession of the ball and the other team gains possession. This happens in a variety of ways, in general either they occur through effective defense or offensive mistakes.
A violation is a turnover like a foul, but more focused on the rules of the game like dribbling, and timing rules. Violations result in a turnover and in some cases free throws in addition to possession of the ball. Here is a list of violations in basketball:
Not all turnovers result in a dead ball. Rebounds and steals are turnovers, but the ball remains live and play continues. If any type of foul or violation is called by a referee, it's a dead ball and the ball and must be brought back in with a throw-in or jump ball. A deal ball will also occur if the ball goes out of bounds. This is a turnover when the ball is last touched by the offense therefore changing possession of the ball.
The boundary lines on a basketball court are the sidelines and baselines. If a player steps on or crosses these boundary lines with the ball he is out of bounds. Stepping out of bounds results in a turnover. After a player steps out of bounds, the other team must put the ball into play with a throw-in.
You can learn more about throw-ins in Basketball Throw Ins.
A rebound is a when a player catches the ball after a shot attempt misses the net. Rebounds can happen off the backboard or out of the air with an airball. Rebounds are considered turnovers because the possession changes, but the ball remains live.
A steal is when a defensive player takes the ball either from an intercepted pass or by swiping the ball out of the dribbler's hands. After a steal, the ball remains live and play continues. Steals are a huge part of the game, as good defenses excel at taking the ball from the opposition. The defense can force turnovers by using a press defense, setting traps, and using active hands.
A foul is a turnover that happens when a player impedes an opposing player on the court verbally or physically. There are lots of fouls in basketball around shooting, unsportsmanlike conduct, and physical contact. Here are the types of fouls in basketball: