What is the main function of leaves?

Leaves are the primary sites of photosynthesis in plants. This process involves the absorption of sunlight, water, and carbon dioxide to produce glucose and oxygen. Glucose is used as energy for the plant, while oxygen is released into the atmosphere as a byproduct. Leaves also play a crucial role in the transpiration process, where water is drawn up through the roots and stems of the plant and released into the air through small pores on the surface of the leaves called stomata. Additionally, leaves help regulate the plant's temperature by controlling the amount of sunlight they absorb and reflecting excess heat. Leaves also serve as a protective barrier against pests, pathogens, and environmental stresses.