Basketball is a team sport in which two teams of five players try to score points by throwing or "shooting" a ball through the top of a basketball hoop while following a set of rules. Basketball is one of the most popular and widely viewed sports in the world.
A regulation basketball hoop consists of a rim 18 inches (45.7 cm) in diameter and 10 feet (3.05 m) high mounted to a backboard. A team can score a field goal by shooting the ball through the hoop during regular play. A field goal scores two points for the shooting team if a player is touching or closer to the hoop than the three-point line, and three points (a "3 pointer") if the player is "outside" the three-point line. The team with more points at the end of the game wins, but additional time (overtime) may be issued when the scores of both teams are the same. The ball can be advanced on the court by bouncing it while walking or running (dribbling) or passing it to a teammate. It is a violation (traveling) to walk with the ball, carry it, or to double dribble (to hold the ball and then resume dribbling).
Various violations are generally called "fouls". Disruptive physical contact (a personal foul) is penalized, and a free throw is usually awarded to an offensive player if he is fouled while shooting the ball. A technical foul may also be issued when certain infractions occur, most commonly for unsportsmanlike conduct on the part of a player or coach. A technical foul gives the opposing team a free throw.
Basketball has evolved many commonly used techniques of shooting, passing, and dribbling, as well as specialized player positions and offensive and defensive structures (player positioning) and techniques. Typically, the tallest members of a team will play "center", "small forward", or "power forward" positions, while shorter players or those who possess the best ball handling skills and speed play "point guard" or "shooting guard".
While competitive basketball is carefully regulated, numerous variations of basketball have developed for casual play. Competitive basketball is primarily an indoor sport played on carefully marked and maintained basketball courts, but less regulated variations are often played outdoors in both inner city and rural areas.