The term "vegan" is a political term as well as a simple description.
The simple description is a strict vegetarian (no animals or dairy in diet) who also abstains from wearing or using animal products in cosmetics and fashion and home. I think that veganism also includes abstaining from honey, but that's up for debate in some circles, since veganism is also a political term... political in the sense that the private values are made public (thus political).
What you feed your family or your animal friends is not really usually considered part of veganism, but there's no consensus there. You do not have to be involved in animal conservation to be vegan, but breeding animals tends not to be so "vegan"... but that usually applies to breeding animals for profit rather than conservation.
I think that the term vegan is a term that is self-taken, rather than given. You have to "claim" veganism, and as long as you fit the basic strict vegetarianism thing and also avoid animal products in clothing and home as much as possible (there is often a long transition for folks until they replace their leather shoes with vegan wares, for example), then the term can be aptly claimed.
"The worker has the right to leave his boss, but can she do it? And if she does quit him, is it in order to lead a free life; where she will have no master but herself? No, she leaves to sell herself to another employer. She's driven by the same hunger. Thus the worker's liberty is only a theoretical freedom, lacking any means of realization; an utter falsehood."