Hello candidate,

The process of photosynthesis in plants to make their own food can be categorised broadly into two phases- light reaction and dark reaction.

Light reaction is the initial step of photosynthesis where plant absorbs light energy from the atmosphere to produce ATP molecules. the second step of photosynthesis is known as dark reaction where the ATP molecules produced by a light reaction gets used by the plants in order to prepare its food in the form of glucose.

Hope this information was helpful!!