The primary function of the leaves of a plant is to facilitate photosynthesis, the process by which plants convert sunlight into energy. Leaves contain chlorophyll, the green pigment that absorbs light energy, primarily from the sun. During photosynthesis, plants take in carbon dioxide from the air and water from the soil, using sunlight to transform these inputs into glucose and oxygen. This process is vital for plant growth and development, as the glucose produced serves as a source of energy and building blocks for growth. Additionally, leaves help regulate gas exchange and transpiration, contributing to overall plant health.