What is a changeup?

Question

The changeup is the staple off-speed pitch, usually thrown to look like a fastball but arriving much slower to the plate. Its reduced speed coupled with its deceptive delivery are meant to confuse the batter's timing. It is meant to be thrown the same as a fastball, but simply farther back in the hand, which makes it release from the hand slower but still retaining the look of a fastball. A changeup is generally thrown 8-15 miles per hour slower than a fastball