Leaves are the green, flat parts of a plant that grow from its stems or branches. They play a crucial role in photosynthesis, the process by which plants use sunlight to make their own food. Leaves come in various shapes and sizes, and they often have a smooth or jagged edge. The green color comes from a pigment called chlorophyll, which helps capture sunlight. In addition to making food, leaves also help plants breathe. Tiny openings called stomata allow gases like oxygen and carbon dioxide to enter and exit. During the day, leaves release oxygen, which is essential for animals and humans to breathe.