What is the term for the area of the earth where all living things exist?

The term that describes the area of the Earth where all living things exist is known as the biosphere. This encompasses all ecosystems and living organisms, including animals, plants, and microorganisms. The biosphere is crucial for life as it interacts with other spheres of the Earth, such as the atmosphere (which contains the air we breathe), the hydrosphere (which includes all water bodies), and the geosphere (which comprises the Earth's physical materials and landforms). The biosphere is vital for maintaining the balance of ecosystems, facilitating processes like photosynthesis and decomposition, and supporting biodiversity, all of which are essential for the survival of living organisms.