Final answer:
Hot, liquid rock beneath Earth's surface is termed magma, which can form through several processes and solidifies to become igneous rocks when it cools.
Step-by-step explanation:
The hot, liquid rock beneath Earth's surface is termed magma. Magma forms in various ways, including through the lowering of melting temperature by adding volatiles (such as water) to the mantle above a subducting plate, by decompression melting, and by conduction, which involves a general increase in the temperature of rock. The mantle is the largest part of Earth's interior and lies between the crust and the core; it is made of solid rock that can deform and flow slowly. Mantle rock becomes magma when it melts due to increased temperatures, decreased pressure, or the presence of volatiles. Igneous rocks form when this magma cools and solidifies, either below the surface as intrusive rocks, or on the surface as extrusive rocks when magma emerges as lava through volcanoes or rifts.