1. Lithosphere: This is the solid, rocky outer layer of Earth, including the crust and the uppermost part of the mantle. It's what we stand on and what makes up mountains, valleys, and the ocean floor.

2. Hydrosphere: This sphere encompasses all the water on Earth, including oceans, lakes, rivers, groundwater, and even the water vapor in the atmosphere. It plays a crucial role in regulating Earth's climate and supporting life.

3. Atmosphere: This is the layer of gases that surrounds Earth. It protects us from harmful radiation from the sun and is responsible for weather patterns. It's made up primarily of nitrogen and oxygen.

4. Biosphere: This sphere encompasses all living things on Earth, from microscopic bacteria to giant whales. It interacts with all the other spheres, influencing and being influenced by them.

These four spheres are interconnected and constantly interact with each other, creating a complex and dynamic system.