EF-S lenses are designed ONLY for crop APS-C cameras. They will not work on a full-frame body, and could damage the latter if attached.
Because the APS-C sensor is smaller than full frame, the image circle needed to be projected onto it does not need to be so big. With this in mind, the optics are designed to only target a smaller area. On Canon lenses, you will notice a 'flange' at the back of the lens, which extends just a tiny bit into the camera body when attached (about 3-4mm). This is fine on an APS-C body camera as the sensor, and therefore mirror is smaller, so when the smaller mirror flips up, it still clears this flange. Were you to attach an EF-S lens to a full frame camera such as the 5D MkII, the larger mirror would hit the flange and in best case scenario your picture will turn out half-dark, but in the most likely scenario you will damage the mirror box assembly!
So do not use an EF-S lens on a full-frame body!!
Annoyingly (said in jest), Nikon crop (DX) lenses do not have this problem. You can freely attach a DX lens to a Nikon FX (full frame) body, and the camera automatically senses it, shows a new frame line in the viewfinder that shows you your area that will be recorded, then only this area is saved to the file! Very clever.