Plantae, commonly known as plants, is a diverse kingdom of living organisms that primarily engage in photosynthesis to produce energy. This group includes a wide variety of species, from tiny mosses to towering trees, all of which play a crucial role in Earth's ecosystems by providing oxygen and serving as the foundation of food chains. Plants are characterized by their ability to convert sunlight into chemical energy through chlorophyll, found in their cells. They are essential for life on Earth, supporting countless species, including humans, by offering food, shelter, and raw materials for various industries. Photosynthesis is a key process that enables this remarkable transformation of energy.