What type of rock forms from the cooling and solidification of magma or lava?

Igneous rock forms from the cooling and solidification of magma or lava. When magma, which is molten rock beneath the Earth’s surface, rises and cools, it crystallizes to form intrusive igneous rocks, such as granite. Similarly, when lava, which is the molten rock that erupts on the Earth’s surface, cools, it solidifies into extrusive igneous rocks, like basalt. The defining characteristic of igneous rocks is that their formation is directly linked to the processes involving molten rock, making them distinct from sedimentary and metamorphic rocks, which are formed through different geological processes.

Sedimentary rocks are formed from the accumulation and compaction of sediments, while metamorphic rocks arise from the alteration of existing rocks due to heat and pressure. Volcanic rock is often used interchangeably with extrusive igneous rock but is not classified separately in geologic terms as a distinct rock type like igneous is. Therefore, the definition and formation process align specifically with igneous rocks as the correct answer.