The type of rock that forms from cooled magma or lava is known as "igneous rock." There are two primary categories of igneous rock: intrusive and extrusive. Intrusive igneous rocks form when magma cools and solidifies beneath the Earth's surface, leading to coarse-grained textures, while extrusive igneous rocks occur when lava cools rapidly on the surface, resulting in fine-grained textures. Examples of igneous rocks include granite (intrusive) and basalt (extrusive). These rocks play a crucial role in the Earth's geology, influencing landscapes and ecosystems.