There are also difference during the conception of these wines.
For champagne for example, you have a lot of reglementations for the alcoolic degree of the juces, for the "acidity" of the wines, and after that a lot of reglementations concerning the press and vinification of the wine.
In this french region, all the wines are tasted to be commercialized. It's a test for all the champagnes, to obtain a better quality.
In champagne the grape harvest are made only by hand, to select the quality and let the bad grapes.
The press of the juces is also really important, you dont have to obtain a spicy taste in the juces, that's why champagne producters all have some press that make a fine work to obtain only the juice and not the "raffle".
Another difference for these wines is also situated in the bubbles.
Some of these wines have bubble only by adding some carbonic gaz (excuse me i'm not sure of this therm, my english isn't good enough ...), and in other situation like champagne, it's a real work of fermentation of the wines, in the bottle.
Wish i did help you, and you understood all i said
