The extent of the Earth's atmosphere is referred to as the atmospheric layer, which includes several layers, such as the troposphere, stratosphere, mesosphere, thermosphere, and the exosphere. This atmosphere extends approximately 10,000 km above the Earth's surface but is densest within the first 10-15 km. It plays a crucial role in protecting life by regulating temperature, filtering harmful solar radiation, and facilitating weather patterns. Understanding this extent is important for weather phenomena, climate studies, and environmental science.