A leaf is a flat, green part of a plant that grows from its stem or branch. Leaves are essential for photosynthesis, the process by which plants use sunlight to make their food. They capture sunlight and convert it into energy, helping the plant grow and thrive. Different plants have various types of leaves, such as broad maple leaves or needle-like pine needles. In addition to their role in photosynthesis, leaves also help regulate water loss through tiny openings called stomata. These openings allow gases like carbon dioxide to enter and oxygen to exit. Leaves come in many shapes and sizes, contributing to the beauty of nature and the diversity of plant life.