A game played on a rectangular court between two teams of five players each with the primary objective of shooting or tossing an inflated ball or the basketball (approximately 9.4 inches (24 cm) in diameter) through a goal, which consists of a basket mounted 10 feet above the floor on a backboard, and to attempt to prevent the opponents from scoring.
The basket measures 18 inches (46 cm) in diameter mounted 10 feet (3.048 m) high to a backboard at each end of the court.
The essence of basketball is this: The team in ball possession attempts to shoot the ball through its own hoop, while the other prevents it from doing so, and vice versa.
A field goal is worth two points, unless made from behind the three-point line, when it is worth three. After a foul, timed play stops and the player fouled or designated to shoot a technical foul is given one or more one-point free throws.
The team with the most points at the end of the game wins, but if regulation play expires with the score tied, an additional period of play (overtime) is mandated.
Players advance the ball by bouncing it while walking or running (dribbling) or by passing it to a teammate, both of which require considerable skill.
On offense, players may use a variety of shots—the lay-up, the jump shot, or a dunk; on defense, they may steal the ball from a dribbler, intercept passes, or block shots; either offense or defense may collect a rebound, that is, a missed shot that bounces from rim or backboard. It is a violation to lift or drag one's pivot foot without dribbling the ball, to carry it, or to hold the ball with both hands then resume dribbling.
Players may dribble the ball or pass it to a teammate, but they may not walk or run with the ball.
The game is conducted by a referee assisted by an umpire. These two officials have equal responsibility for calling violations and fouls. Each period of the game is started by a jump ball in the center of the curt (only the first period in one professional league), and play is continuous except for time-outs, violations, and fouls.
When one team scores, the other team must put the ball in play from outside the end line underneath the basket.
The game is divided into four quarters or two halves and the team with the most points at the end of the playing time is the winner. If the score is tied at the end of the regulation play, a short overtime period is played.