Here's why:

* Magma is molten rock found beneath the Earth's surface.

* When magma rises to the surface and erupts from volcanoes, it's called lava.

* As magma or lava cools and solidifies, it crystallizes into igneous rock.

There are two main types of igneous rocks:

* Intrusive igneous rocks form when magma cools slowly beneath the Earth's surface, resulting in larger crystals. Examples include granite and gabbro.

* Extrusive igneous rocks form when lava cools quickly on the Earth's surface, resulting in smaller crystals. Examples include basalt and obsidian.