What is the most well known product of the Champagne region?

The best-known product of France's Champagne region is Champagne, the sparkling wine.

Champagne is produced in northeastern France under strict appellation rules. To carry the name Champagne in the European Union and many other countries, the wine must come from the legally defined Champagne wine region and follow regulated production practices. The region lies roughly 160 kilometres east of Paris, with Reims and Épernay serving as major commercial centers.

Most Champagne is made from three principal grape varieties: Chardonnay, Pinot noir, and Pinot Meunier. Its characteristic bubbles develop through a second fermentation in the bottle, traditionally called the méthode champenoise for wines actually made in Champagne. Similar sparkling wines made elsewhere are generally described as méthode traditionnelle, Cava, Prosecco, or other regional names.

The region also produces smaller quantities of still wines such as Coteaux Champenois and Rosé des Riceys, but sparkling Champagne is overwhelmingly its signature product. A common mix-up is using “champagne” as a generic name for any sparkling wine.