The stages in respiration

There are 3 main steps involved in aerobic respiration. These are:

glycolysis

The Krebs cycle

The electron transport chain (ETC)

The first 2 steps both produce ATP. They also generate hydrogen atoms, in the form of a proton and a high energy electron.
Both the proton and the electron will be passed on to electron carriers -NAD and FAD.

During the electron transport chain the protons and energy from the electrons will be used to generate the greatest amount of ATP.