An error in baseball is a mistake made by a defensive player, such as failing to catch a ball or making a poor throw, that allows a batter or base runner to advance or reach a base safely. It affects a player's fielding percentage and can have significant implications on the game's outcome. An error does not result in a hit for the batter but allows the offensive team additional opportunities to score. The official scorer determines whether a play should be recorded as an error based on the player's actions and the circumstances.