What does intrusive and extrusive mean?

Answer 1

These two terms are used to classify igneous rock. Intrusive igneous rock has solidified from magma, below the surface of the Earth. Extrusive igneous rock has solidified from lava, at or near the surface of the Earth. Intrusive rock displays a coarse-grained rock texture, a result of the slow cooling of magma. Extrusive igneous rock will display either a fine or a glassy texture, depending on the speed of solidification of the lava.