Animals use light to see. Plants collect light for a very different reason: to make food. Making food with light is called photosynthesis.
Photo means “light,” and synthesis (SIN-thuh-sis) means “to put together.” To make food, a plant puts together light, a green pigment called chlorophyll, carbon dioxide, and nutrients.
For almost all plants, the job of collecting light is up to the leaves. Look at a leaf. You can tell what kind of light the plant lives in—low, medium, or bright. Some leaves that live mostly in shade are built to collect more light. Others are built to make good use of low light. In a sunny area, leaves have a different problem: heat. They have no trouble collecting light. But they have to stay cool in the hot sun.