there is a nema 14-50 wall plug (similar to you have a nema 5-15 (or 5-20 ) wall plug which is the regular plug you recognize in your home). just like you have a toaster or something that plugs in to a regular outlet and has either a 2 prong or 3 prong male plug that goes into a female outlet, 14-50 works the same way from a usage stand point.
The difference from a usage standpoint is the shape of the plugs are different, to prevent things that are not supposed to be plugged into them from being plugged into them.
NEMA connector - Wikipedia
14-50 is simply a type of wall plug from a consumer point of view. From the "wiring" point of view it has different requirements than your regular wall plug but if you are having someone install it you dont need to worry about that part.