On the basis of occurrence, classify Igneous Rocks.

On the basis of occurrence, Igneous Rocks are of two types:

1. Intrusive Igneous Rocks — The rocks that are formed due to solidification of magma below the Earth's surface and remains surrounded by pre-existing rock are called Intrusive Igneous Rocks.
2. Extrusive Igneous Rocks — The rocks that are formed due to solidification of magma above the Earth's surface are called Extrusive Igneous Rocks.