Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish dirt from soil by restricting the former term specifically to displaced soil. The pedosphere interfaces with the lithosphere, the hydrosphere, the atmosphere, and the biosphere. Collectively, Earth's body of soil, called the pedosphere, has four important functions: All of these functions, in their turn, modify the soil and its properties.