What is a infield fly rule in softball?

An 'infield fly' is a term in Baseball where the ball shoots extremely high and is caught in the infield. This is important because it prevents a 'sacrifice fly' which would be a fly ball in the outfield where a base runner could possibly advance. It is also a rule in softball. If the ump calls "infield fly" then its an automatic out if there are runners on 1st and second with less than 2 outs or if bases are loaded with less than 2 outs. It is there so the team cannot get all three outs out of one play. If you leave the base after the ball has hit the mit of an infielder or has touched the ground you are at your own risk and is considered a steal.