Photosynthesis involves the conversion of light energy from the sun into chemical energy that is stored in organic compounds like glucose. It occurs through two main stages - the light-dependent reactions in which ATP and NADPH are produced, and the light-independent Calvin cycle in which carbon dioxide is fixed to produce carbohydrates. Chlorophyll is the primary photosynthetic pigment located in chloroplasts that absorbs sunlight to drive these reactions that ultimately result in the production of oxygen and energy-rich organic compounds.