Igneous rock is formed from volcanic activity. This type of rock is created when magma rises to the Earth's surface and cools, either rapidly upon eruption or slowly beneath the surface. There are two main types of igneous rock: intrusive (or plutonic) rock, which forms from slower cooling magma beneath the Earth’s crust, resulting in coarse-grained textures, and extrusive (or volcanic) rock, which cools quickly on the surface, leading to finer-grained textures. Common examples include granite (intrusive) and basalt (extrusive).