Vegan vs. Vegetarian?

What are your thoughts or reasons for your dietary choices? I've been a vegetarian in the past, for years. But I've gone back to eating some meats occasionally, this past year or so. But the bottom line is meat makes me feel gross. So I've made a promise to myself to begin my vegetarian diet again-or should I go further? Tell me why you have or would not choose to be vegan over vegetarian?