* Light energy: This is the primary input, captured by chlorophyll and other pigments in the thylakoid membranes.

* Water: This is split to provide electrons and protons (H+ ions). The oxygen byproduct is released as a gas.

* ADP and inorganic phosphate (Pi): These are used to produce ATP (adenosine triphosphate), a molecule used for energy storage.

* NADP+: This is reduced to NADPH, a reducing agent used in the Calvin cycle.

In summary, the light reactions use light energy, water, ADP, Pi, and NADP+ to produce ATP, NADPH, and oxygen.