Softball is a team sport in which a ball, eleven to twelve inches in circumference, is thrown by a player (called a pitcher) towards an opposing team player called a batter who attempts to hit the ball with a round, smooth stick called a bat. The ball itself is also called a softball. Scoring is accomplished by the batter hitting the ball as far away as he/she can and then running and touching a series of four markers on the ground called bases before the opposing team's fielders return the ball. The batter can stop play at anytime by stopping on one of the diamonds if he feels that he cannot get ‘home' safely. If the opposing team can throw the ball to the runners next diamond before he gets there he is ‘out' and no run is scored. Softball is a direct descendant of baseball (sometimes referred to as hardball to differentiate the two), but differs from it in several ways, of which the chief four are:

• The ball is always pitched (thrown to the opposing team's batter) underarm - in other words, it is released when the hand is below the hip and no further away from the body than the elbow - while in baseball the ball may be released in any position and is usually thrown overarm or sidearm at greater speeds.
• The ball is larger, softer (hence the name), less dense, and heavier than a baseball.
• The fields used for softball are normally smaller.
• The game is seven innings long, as opposed to nine in baseball. Softball games tend to take between one and two hours to complete, as opposed to around three hours for most baseball games.

Softball is said to be the most popular participant sport in the United States. An estimated 56 million Americans will play at least one game of softball during a year and is played by both men and women.

Softball has been an Olympic sport for women since 1996 but has now been dropped although there are moves afoot to re-establish it. The International Softball Federation holds world championships every four years, the latest being held in June 2005.