Answer:
The crust is the outer layer of the Earth. It is the solid rock layer upon which we live. It is either continental or oceanic. Continental crust is typically 30-50 km thick, whilst oceanic crust is only 5-10 km thick. Oceanic crust is denser, can be subducted and is constantly being destroyed and replaced at plate boundaries. Continental crust is older, lighter and cannot be destroyed.
