Intrusive igneous rocks are formed when magma cools and solidifies beneath the Earth's surface. Examples of intrusive igneous rocks include granite, diorite, and gabbro.

Extrusive igneous rocks are formed when magma cools and solidifies on the Earth's surface. Examples of extrusive igneous rocks include basalt, andesite, and rhyolite.

Pyroclastic igneous rocks are formed when volcanic ash, cinders, and bombs are ejected from a volcano and then cool and solidify. Examples of pyroclastic igneous rocks include tuff, breccia, and pumice.