Champagnes or sparkling wines?

Both, but the choice depends a lot on the occasion and the financial availability. However, the famous phrase "all Champagne is sparkling wine, but not all sparkling wine is Champagne" cannot be over-emphasized.

But let the occasion speak for itself, and just stick to the following note: Champagne is all sparkling wine exclusively produced in this demarcated region of France.

Sparkling wine is a wine with carbonic gas originating from the natural second fermentation of the already fermented wine, without the artificial addition of carbonic gas, and made from its own grapes. Sparkling wines are produced in almost all wine-producing countries, with the majority being produced in France, which created some methods for its production, namely Champagne (designation only attributed in the region of origin). These influences contributed to the appearance of different types of sparkling wines in other countries: Prosecco and Asti (Italy), Sekt (Germany), Cava (Spain), and our Sparkling wines (Portugal). 

Prosecco is an Italian white wine, produced in the variants spumante, frizzante, and Tranquillo, depending on the degree of perlage. It is produced from the glera grape, a vine variety, formerly known as prosecco, originating from the Veneto region of Italy. The name change was an attempt to end confusion between the type of wine and the grape.

Only two regions are entitled to the controlled appellation of origin: the towns of Valdobbiadene and conegliano.