What is a sacrifice fly?

A Sacrifice Fly is only credited when a baserunner scores on a fly ball out. In this case the batter is given an RBI (run batted in) and not charged with an at bat (you will be 0-0). Moving a runner from 1st to 2nd or from 2nd to 3rd with a fly ball out may be admirable, but is not counted as a Sacrifice Fly (you will be 0-1)