Here's a breakdown:
* Molten material: This is magma when it's underground and lava when it erupts on the surface.
* Cooling and hardening: As the molten rock loses heat, it solidifies.
* Igneous rock: This is the resulting rock type.
There are two main types of igneous rocks based on how they form:
* Intrusive igneous rocks: These form when magma cools and solidifies *inside* the Earth's crust. They tend to have larger crystals due to the slower cooling process.
* Extrusive igneous rocks: These form when lava cools and solidifies *on* the Earth's surface. They often have smaller crystals because the lava cools quickly.
