A wine will have an alcoholic content between 8% to 15% on an average which is achieved as a result of fermentation. For eg. wines are commonly made from grapes like Sauvignon Blanc, Chardonnay, Merlot, Pinot Noir.
A fortified wine will have an alcoholic content between 15 to 22% on an average and this is achieved by a combination of fermentation & grape spirit being added to the wine. Famous fortified wines would be port & sherry.