Igneous rock is the type of rock formed from cooled magma. When magma, which is molten rock located beneath the Earth's surface, rises and cools either below the surface as intrusive rock or on the surface as extrusive rock, it solidifies into igneous rock. The cooling process can vary in speed: slow cooling allows larger crystals to form, resulting in coarse-grained rocks like granite, while rapid cooling produces fine-grained rocks like basalt. Igneous rocks are fundamental to the rock cycle and provide valuable insights into geological processes.