Oxidative phosphorylation is responsible for the production of ATP occur in the electron transport chain (ETC)
Another way to synthesize ATP is through substrate level phosphorylation where a substrate with phosphate molecule attached to it will donate its phosphate to ADP molecule hence ADP is converted to ATP, a three-phosphate high energy molecule. Bear in mind that production of ATP molecule requires high energy therefore it is endergonic reaction. The energy is supplied through breaking the bond in the substrate molecule to release a phosphate group, and this reaction is exergonic.
Lets view an animation on Oxidative Phosphorylation via this link