What are Igneous Rocks?
Igneous rocks are rocks formed by a volcano. they can be formed inside the volcano or outside. Inside is intrusive, and outside is extrusive. When you hear the word extrusive, you will probably think outside. Intrusive of course, is the opposite. You will learn more about this in the next pages.
http://www.buzzle.com/articles/how-are-igneous-rocks-formed.html
Fun Fact
Did you know that the magma in the volcano is called lava when it is outside?