As part of my self-definition, I should also point out that I am a vegetarian; have been for nearly 15 years now. (my, how time flies) It always follows that I am asked why, and what kind of vegetarian am I, really? There are a few definitions; for my purposes, there are 3. For your enlightenment, they are the Ovo-Lacto (who eats no meat but does eat eggs and dairy), the Lacto (no meat or eggs, but yes to dairy) and Vegan (who neither eats nor uses any animal products at all, as much as this is possible these days). Check out the Vegetarian Times, or this site for Vegan info.
You can not say that vegetarians are all of a kind, any more than you can say that people who eat hamburgers are all of a kind. Well, I suppose you could say it, but it wouldn't be strictly true, nor useful. However, a new term making the rounds is flexitarian -- apparently a person who eats mostly non-meat, but will throw in a good chunk of chicken or fish now and again. Due to what, I have no idea. I have to say that I draw the line there...if you eat meat you are not a vegetarian.
As for myself, I am an ovo-lacto, with leanings toward vegan. In case you were curious.