Here's a breakdown:

* Igneous rocks are formed from the cooling and solidification of magma (molten rock) or lava. They can be found on the surface, like basalt, or deep within the Earth, like granite.

* Sedimentary rocks are formed from the accumulation and cementation of sediments, which are fragments of other rocks, minerals, or organic matter. Examples include sandstone, limestone, and shale.

* Metamorphic rocks are formed when existing rocks are transformed by heat, pressure, or chemical reactions. Examples include marble, slate, and gneiss.

The crust is divided into two main types:

* Continental crust is thicker and less dense, made mostly of granite. It forms the continents.

* Oceanic crust is thinner and denser, made mostly of basalt. It forms the ocean floors.