The document discusses the four major spheres of Earth: the atmosphere, biosphere, hydrosphere, and geosphere. It provides details on the composition and key features of each sphere. The atmosphere contains different layers and is mostly nitrogen and oxygen. The biosphere is the zone of life on Earth, structured through food chains. The hydrosphere contains all water on the planet, including oceans, lakes, ice, and vapor. The geosphere is the solid part of Earth from the core outward, including rocks and minerals. Earth system science studies how these spheres interact constantly, affecting one another.