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

Igneous rock is formed through the cooling and solidification of magma or lava, which makes it distinct from other rock types. When magma cools beneath the Earth's surface, it crystallizes into intrusive igneous rocks, such as granite. Conversely, when lava cools on the Earth's surface, it results in extrusive igneous rocks, such as basalt. The key characteristic of igneous rocks is that they originate from molten material, distinguishing them from metamorphic rocks, which originate from existing rocks that have been altered by heat and pressure, and sedimentary rocks, which form from the accumulation and compaction of sediments. Fossil rock, while it may suggest the presence of fossils, is not a recognized geological classification. Thus, igneous rocks are the direct product of molten material cooling, making it the correct answer in this context.