As an example three famous Burgundy wines use the Chardonnay grape, but they have very different tastes:
Côte de Beaune includes the wines from Puligny-Montrachet, Chassagne-
Montrachet and Corton-Charlemagn.
Chablis comes from the four Appellations around the town of Chablis and associated
with the original grading of the vineyards. See the post: Chablis; One of France's
Finest White Wines and Chablis the Town.
The Mâconnais region produces the famous Pouilly-Fuissé and more. All these
regions produce wines made with the Chardonnay grape.
Each region produces wines with a different tastes.
In the French world of food and wine grading, AOP is the big one; even for the locals an AOP is the most impressive of all the many grades printed on the labels of French foods and wines. The fact that these wines' ratings may have been handed out over 80 years ago and not checked since worries very few.
For more about AOP and its use in French foods and more see the post: AOC and AOP on France's Foods and Wine labels?
the previous Vin de Pays label.