Glycolysis can be divided into two stages:

In the first stage, glucose is energized by the addition of energy from ATP.

In the second stage, energy is transferred to the energy carrying molecules, NADH and ATP.
    NADH is produced by a redox reaction.
    ATP is produced by a substrate-level phosphorylation reaction.

During Glycolysis, 2 NADH molecules, 2 ATP(net) molecules and 2 pyruvic acid molecules are produced.