The Earth is divided into Three Main Layers: the crust, which is the Outermost solid shell; the mantle, a Semi-solid layer Beneath the crust that Flows slowly over Geological Time; and the core, which is further divided into a Liquid outer core and a Solid inner core. These layers are distinguished by their Chemical Composition and Physical Properties, playing crucial roles in Earth's Geological Activities, including Plate Tectonics and the Generation of the magnetic field.