I am currently taking a brief course in Technical/Academic Writing. At one point, in passing, the lecturer (who's a researcher in linguistics himself) mentioned that one should not confuse a conference abstract with an article abstract, with the exact phrasing "... that's a whole different story."
Unfortunately, at that moment in time I did not reflect on what those differences might be, but now I am writing a conference abstract I realize that I have never really paid much attention to the fact that I am not writing to a journal. Besides the fact that a conference abstract is preamble to a primarily spoken form presentation (poster/oral) instead of a written one, I don't really see why it would be "a whole different story".
Assuming that there are no differences in requirements and limitations, what are the fundamental differences, between a conference abstract and an article abstract, that one should be aware of?
PS: if it matters, the field I'm mostly concerned about is medical research