A leaf has a complex structure composed of multiple layers. The outermost layer, called the epidermis, provides protection and minimizes water loss. Beneath this lies the mesophyll, which contains chloroplasts for photosynthesis. The mesophyll is divided into palisade and spongy layers, maximizing light absorption and gas exchange, respectively. Additionally, veins within the leaf transport water and nutrients, consisting of xylem and phloem. This intricate design allows leaves to efficiently harness sunlight while maintaining adequate hydration and nutrient flow.