1. Crust: The outermost and thinnest layer

- Oceanic crust: Thin and dense layer primarily found beneath the oceans. Composed mainly of basalt and other dense rocks.

- Continental Crust: Thicker and less dense layer found beneath continents. Primarily made of granite and other lighter rocks.

2. Mantle: The thickest layer, located beneath the crust.

- Upper mantle: Solid, rigid, and relatively hot. Composed of silicate minerals such as olivine and pyroxene.

- Lower mantle: Plastic and more viscous due to higher temperatures and pressure.

3. Outer Core: Liquid layer made primarily of iron and nickel. Responsible for generating Earth's magnetic field through a process called the geodynamo.

4. Inner Core: Solid, dense, and extremely hot center of the Earth. Composed mostly of iron with some nickel.