In the ATP cycle, a phosphate group is cut off of
ATP to form ADP, absorbing energy.
ATP to form ADP, releasing energy.
ADP to form ATP, absorbing energy.
ADP to form ATP, releasing energy.
When the terminal (third) phosphate is cut loose, ATP becomes ADP (Adenosine diphosphate; di= two), and the stored energy is released for some biological process to utilize. The input of additional energy (plus a phosphate group) "recharges" ADP into ATP (as in my analogy the spent batteries are recharged by the input of additional energy).
