Essentially they are the same. In fact they are usually just two different terms for the same thing. However, body 'sculpting' can mean one is more inclined to defining and shaping, where as body 'building' can mean one is more inclined to adding mass and size.
Exactly. Same thing, just beware anyone who tries to claim they're doing a routine that would actually help "shape" a muscle group to a specific way, since it can't be done. You can gain muscle mass overall with weight training, but the two continual truths are that A) you can't spot reduce fat on a specific location unless you plan to get lipo, and B) you can't change the shape of a muscle in a specific manner, it can get larger or smaller according to your training, but you can't (for example) do anything that would specifically target JUST the lower part of the pectorals, anything you would do for chest will affect the entire muscle overall.