WHAT'S THE DIFFERENCE BETWEEN A "TREKKIE" AND A "TREKKER"?
"Trekkie" is obviously the more common term, the one found in some dictionary or something or other. Anyway, many people have assigned different definitions distinguishing between a "Trekkie" and a "Trekker"--one's a casual fan, one's an obsessed fanatic, one's got a life, one's a loser--but their definitions tend to vary and switch (depending on which side of the Trekkie/Trekker argument they stand on).
But my basic definition of the difference between a "Trekkie" and a "Trekker" gets down to the root of the issue, and I think it's one most will agree is true:
Trekkie: a Star Trek fan.
Trekker: what a Star Trek fan who doesn't like the term "Trekkie" (because they think it's demeaning, or indicates a group of Trek fans of a different kind) calls himself or herself.
I'm not saying that "Trekkers" are snobs--they just don't like "Trekkie," which some people might feel is a belittling term used by non-Trek fans for our ilk.
As for me, I have no qualms about being called a Trekkie or a Trekker, but to be "politically" correct, I refer to other Trek fans as "Trekkers" so as not to alienate those who do not like being called "Trekkies."