Photosystems are essential components of the process of photosynthesis, which occurs in the chloroplasts of plant cells. They consist of a collection of proteins and pigments, including chlorophyll, that capture light energy from the sun. There are two main types of photosystems: Photosystem I and Photosystem II, each playing a unique role in converting light energy into chemical energy. During photosynthesis, these photosystems work together to generate energy-rich molecules like ATP and NADPH. Photosystem II absorbs light first, splitting water molecules to release oxygen, while Photosystem I further processes the energy to produce the necessary compounds for the plant's growth and metabolism.