When you order a flight of wine, it's usually a selection of 3 small glasses of similar wines to taste and compare (same type of wine from different regions, or several bold reds, or three different years of the same wine). By tasting in this way, you may choose which to purchase in a greater quantity (glass or bottle). Also done with beer, whisky, cheese, and other agricultural products. Madly popular in the US among yuppies. A wine flight, which is a tasting pour (2.5 oz.) of four different wines served next to each other, is the perfect way to compare, contrast and explore. The term belongs to the world of foodies. It's a succinct way of describing a wine tasting setup. It doesn't inhabit the world of snobbishness or puffery that some wine descriptors do. Although it started with wine, it's now used in other tasting contexts.