What is the difference between a matopexy and mastectomy?

So I am having surgery on march 14,2017 and I keep forming capsular contracture on my breast so the surgeon told me that she was going to do an capsuletomy with an immediate insertion of a breast prosthesis following a mastopexy, or mastectomy what exactly does that means I know its a reconstruction but I'm not sure on what exactly that means the explaining she said I didn't really understand