Well, if we're talking about authentic Italian and Greek dressings, there's really not that much difference. They're both basically vinaigrettes with olive oil, vinegar (for Italian) or lemon (for Greek) and seasonings added. However, if you're referencing the Americanized versions that we're used to seeing in our grocery stores, there are huge differences. Italian dressings come in a wide range of flavors that would be as foreign to someone in Italy as our version of pizza. And our bottled Greek dressings, I'm quite sure, would cause a true Greek cook to just shake his head.