Why do planets become layered as they are being formed?

Planets become layered during their formation due to processes like differentiation, where denser materials sink toward the center while lighter materials rise to the surface. As a planet accumulates mass from dust and gas, heat generated from gravitational compression and radioactive decay causes melting, allowing for the movement of materials. This results in distinct layers, such as a metallic core, a silicate mantle, and a crust, each with different compositions and properties. The layering is further influenced by factors like temperature, pressure, and the specific materials present during formation.