Which type of rock is formed from the cooling and solidification of magma?

Igneous rock is formed through the cooling and solidification of magma, which occurs either below the surface as intrusive igneous rock or after the magma erupts onto the surface as lava and cools, resulting in extrusive igneous rock. When magma cools and crystallizes slowly beneath the Earth's surface, it forms coarse-grained intrusive igneous rocks like granite. Conversely, when magma erupts and cools rapidly on the surface, it forms fine-grained extrusive igneous rocks like basalt.

This process is fundamental to the rock cycle, illustrating how the Earth continuously recycles material. In contrast, metamorphic rocks are generated through the alteration of existing rocks under heat and pressure, while sedimentary rocks form from the accumulation of sediment and organic materials. The term "volcanic" typically describes a type of extrusive igneous rock but is not a formal classification of rock types like igneous, metamorphic, or sedimentary. Thus, igneous is the appropriate answer to the question regarding the cooling and solidification of magma.