The Lithosphere- contains all of the solid land of the planet's crust, the semi-solid land underneath the crust, and even the molten part of Earth’s core.

The Hydrosphere- contains all the water of the planet, which exists in solid, liquid, and gas forms. Water flows as precipitation from the atmosphere down to Earth's surface, as rivers and streams along Earth's surface, and as groundwater beneath Earth's surface. Most of Earth's freshwater, however, is frozen.

The Biosphere
- contains all the planet's living things. This sphere includes all of the microorganisms, plants, and animals of Earth. 

Within the biosphere, living things form ecological communities based on the physical surroundings of an area. These communities are referred to as biomes. Deserts, grasslands, and tropical rainforests are three of the many types of biomes that exist within the biosphere.

The Atmosphere-contains all the air in Earth's system. The upper portion of the atmosphere protects the organisms of the biosphere from the sun's ultraviolet radiation. It also absorbs and emits heat. This sphere is also where weather occurs.

Most Earth events involve interaction between multiple spheres. For example, rain is the movement of water (the hydrosphere) from the atmosphere to the lithosphere where it collects in lakes, rivers, or streams. Water is an important resource for inhabitants of the biosphere.

The Lithosphere- contains all of the solid land of the planet's crust, the semi-solid land underneath the crust, and even the molten part of Earth’s core.

The Hydrosphere- contains all the water of the planet, which exists in solid, liquid, and gas forms. Water flows as precipitation from the atmosphere down to Earth's surface, as rivers and streams along Earth's surface, and as groundwater beneath Earth's surface. Most of Earth's freshwater, however, is frozen.

The Biosphere
- contains all the planet's living things. This sphere includes all of the microorganisms, plants, and animals of Earth. 

Within the biosphere, living things form ecological communities based on the physical surroundings of an area. These communities are referred to as biomes. Deserts, grasslands, and tropical rainforests are three of the many types of biomes that exist within the biosphere.

The Atmosphere-contains all the air in Earth's system. The upper portion of the atmosphere protects the organisms of the biosphere from the sun's ultraviolet radiation. It also absorbs and emits heat. This sphere is also where weather occurs.

Most Earth events involve interaction between multiple spheres. For example, rain is the movement of water (the hydrosphere) from the atmosphere to the lithosphere where it collects in lakes, rivers, or streams. Water is an important resource for inhabitants of the biosphere.