The scientific term for the rocks that are formed from the cooling of the lava are known as the igneous rocks. The igneous rocks are formed from the molten magma inside the volcanoes. The eruption of the magma and its subsequent cooling leads to the formation of the igneous rocks. The igneous rocks formed inside the molten Earth are known as intrusive igneous rocks and the ones formed on the Earth's surface are known as extrusive igneous rocks.
Hence, the answer is 'igneous rocks'.