What "error" means in baseball

In baseball, an error is a defensive misplay that allows the batter or baserunner to advance one or more bases or reach a base safely that they otherwise would not have. Errors can be charged to fielders who mishandle ground balls, drop fly balls, make errant throws, or fail to cover bases properly. While errors can be costly, they do not count against a pitcher's earned run average (ERA) or a team's fielding percentage.