THE CRUST
The Crust--  The crust is the outermost layer of the Earth comprised of low density Granite and basalt about 20-30 miles thick.

"So... what's that mean to me?"

Well, suppose you are holding a basketball.  The part you are touching is the crust, and the bumps you feel are all the mountains and hills.

Low density means that the crust is easily crumbled, smashed, demolished, broken, crushed... well... you get the idea?

Now... there are 2 types of crust.   There is Continental Crust and Oceanic Crust.

(Now, these 2 both make up the crust,
one is just under water and the other isn't.)


 
Continental Crust This crust is basically the mountains, hills, valleys, knolls, and any other land you see. 
It is about 18-24 miles thick.
It is mostly made up of Granite.
Oceanic Crust This crust is basically the ocean floor, the bottom of the sea, or any other area under water.
It is about 2-6 miles thick.
It is made up of Basalt.

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