The primary function of leaves on a plant is photosynthesis, the process by which plants convert sunlight into energy. Leaves contain chlorophyll, the pigment that captures light energy, enabling the plant to synthesize carbohydrates from carbon dioxide and water. This process not only provides energy for the plant's growth and development but also produces oxygen as a byproduct, which is essential for the survival of most living organisms on Earth. In addition to photosynthesis, leaves play vital roles in gas exchange, transpiration, and regulating temperature, contributing to a plant's overall homeostasis and health.