first thing first, it's intrusive igneous rock :v
the difference between them is that:
Extrusive igneous: rock is formed by cooled down lava from volcanic eruption, thus having a smoother surface(fine-grained) with little crystal
Intrusive igneous rock: formed by magma that is trapped within the crust and has a rougher surface(coarse-grained) as it contains more and larger crystal
you can pick one difference frim the above,hope it helps! :)
