An someone please explain the difference between dvw and water pipe as it pertaines to copper pipe fittings thanks tallgrass:o :o :confused: :o

You have thin wall type m water pipe. It has red ink. Type l has blue ink. Dwv has yellow ink, and I don't remember what type k color is. The dwv has a thinner wall and is cheaper. Type l is thicker than type m and typically type m is residential and type l is commercial and type k is used under concrete where you really want a very thick walled pipe.
Water fittings generally are not throated. They abruptly turn. Dwv fittings have a shallower cup and are throated, that is to say, they sweep as they turn.