Recently I overheard a customer at my local scoop shop order lemon sherbet. All the shop could offer her was lemon sorbet, and unfortunately, no one behind the counter could explain the difference.
The word sorbet is really just the French translation of the English word sherbet (often misspelled sherbert). Both words (and the Italian sorbetto) are derived from the Turkish sharbat, a sweetened frozen fruit drink.
Over the years, however, sorbet and sherbet have come to mean different things in this country. Today, sherbet contains egg whites, milk, or gelatin (or a combination) to give it a creamy consistency, while sorbet is made without gelatin, eggs, or dairy products (though it may have pectin or vegetablebased thickeners). The changeover to sorbet started a decade or so ago when savvy marketers started using the French word to refer to new, upgraded, gourmet ices made with more attention to flavor and texture.