The first step of photosynthesis is light reaction, in which photolysis of the water molecules takes place.
The water molecules breaks down into hydrogen, oxygen and electrons in the presence of the light.
The end product is hydrogen which is taken by NADP to form NADPH. The electron is used to convert ADP into ATP. and the oxygen is released into the environment.
Both ATP and NADPH is used as a power source in the production of the glucose during the dark reaction.
