The document defines and describes the environment and its components. It states that the environment encompasses all living and non-living things on Earth and includes the physical, biological, and cultural elements that surround and interact with organisms. The environment has both abiotic (non-living) components like air, water, and land, as well as biotic (living) components like plants, animals, and microorganisms. It then describes the four main segments that make up Earth's environment - the atmosphere, lithosphere, hydrosphere, and biosphere - providing details on their composition and layers.