Basketball is a sport which is played by two teams having five players each on a rectangular court. The purpose of the game is to throw a ball specially made for the game through a hoop of 18 inches (46 cm) in diameter and 10 feet (3.048 m) in height mounted to a backboard at each of the ends of the court. A team can score a point (called field goal) by shooting/throwing the ball through the basket (hoop) during the game. A field goal scores three points for the shooting team (the team which throws the ball through the hoop (basket)), if the player shoots/throws from behind the three-point line/spot, else two points if shot is taken from front of the line. The term field goal refers to a basket scored on any shot/throw but for a free throw. Field goal is the authorized term used by the National Basketball Association (NBA) in their rule book, in their box scores and statistics, and in the referees' rulings. A team can also score by means of free throws, which are worth only one point, wherein they are applicable only after the other team was assessed with certain fouls. The team with the most points or field goals at the end of the game wins. Additional time (also called overtime) is given when the score reaches a tie at the end of regulation. The ball can be taken forward on the court by bouncing it while walking or running or throwing it to a teammate. Conventionally, the tallest and strongest members of the team are called a centre or power forward, whereas slightly shorter and more agile ones are called small forward, and the shortest or those who enjoy the best ball handling skills are known as a point guard or shooting guard.