As defined by J.S. Joffe in 1949, Soil's a natural body consisting of layers (horizons) of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics. In engineering, soil's referred to as regolith, or loose rock material. Soil differs from its parent rock due to interactions between the lithosphere, hydrosphere, atmosphere, and the biosphere. It's a mixture of mineral and organic constituent… (More on Soil)