What does bumpmap texture different from normal texture?

I heard they say textures are more 3d. But im not sure.
Just look at the tutorials.
Bumpmap is when your limbs are bumped or hit then the textures will come out changing your original texture,
Here's a tutorial made by clockworkmonkey.
http://forum.toribash.com/showthread.php?p=1269366

And here are other people who asked about bumpmap
http://forum.toribash.com/showthread.php?t=302813
http://forum.toribash.com/showthread.php?t=275704