The Earth is composed of 4 major components, including:

1. Crust: The outermost layer, ranging in thickness from 5-70 km, which is composed of rocks and sediments.
2. Mantle: The layer beneath the crust, extending to a depth of about 2,900 km, made up of hot, viscous rock.
3. Outer Core: A liquid layer, about 2,250 km thick, composed of iron and nickel.
4. Inner Core: A solid, iron-nickel alloy core at the center of the Earth, about 1,220 km in diameter.