The term ' cremant ' applies to a number of French sparkling wine appellations of which the most important are Alsace, Bourgogne and The Loire: the wines are made by the traditional champagne method and must spend a minimum of nine months on the lees.
Cava predominantly comes from the Catalonia region in Spain but other key producing areas include Navarra, Rioja & Valencia: again traditional method is used as is ageing on the lees & local grape varieties prevail and most Cava is non vintage.
Prosecco is made in North East Italy in 2 defined regions and most Prosecco is produced by the tank method - it is very easy drinking, young and fresh.
Other notable sparkling wine producing countries include Germany, Australia, New Zealand, South Africa & California in the USA.