ADP

An enzyme can make ATP set free the last of its three phosphates. It pops off like the cork out of a pop-gun. As it flies off it absorbs a molecule of water. This can cause dry-joining in two other molecules. What is left is a phosphate and ADP.

Or the phosphate can be joined on to some other molecule, making it in turn spring loaded and ready to fire.

This firing of the end phosphate of ATP is used to power almost all of the work done by every cell on Earth!