I've come across and met a lot of anime fans in the past several years. And the way I see it.. you got your variants of anime watchers. It goes, Rarely -> Occasionally -> Casual -> Fan -> Otakus -> Weeaboos. It's not exclusive, and there's different sub-tiers of it, but for the most part, this is what I see.
--------------------------------------------------------------
People in the Rarely category are the ones who almost never watch, and if they do, it might be whenever it pops up on TV or they see a new series that they watch for a bit, and then after that they don't watch again for long periods of time.
People in the Occasionally category are the ones who watch now and again, whenever they're in the mood to. They watch it a bit more frequent than the Rarely category people, but not enough to be casual. They don't finish any series right away or consistently, they leave it be for a while and come back to it whenever they feel like it.
People in the Casual category are the ones who'll find a series, finish it relatively quickly and then probably move on to another series. They're like your average TV show watchers. Say for example you like The Walking Dead, and you follow up on every episode but you're not concerned if you don't catch it on the air-date. They watch their shows at their own leisure and entertainment. They enjoy it, but they're not going crazy.
People in the Fan category are ones who will watch a series, will probably marathon/all-nighter it and then move onto another series to do so. They probably also read the manga versions, and usually don't have too much of a problem admitting they're anime fans. They're the ones that can give you their opinions on an anime, give you a detailed reason why they feel what they feel and have their own ideas on how the story should've played out. They also can recommend a series that you might be into as well, going off your interests and preferences. They're the ones that tend to buy the DVDs, Blu-Ray copies that support the industry and go to conventions. But at conventions, they're the more laid-back type individuals and you usually find them in the showing rooms or vendor's rooms with the merchandise. They also cosplay, but not avid about it, and at best is a hobby.. though, they wouldn't mind doing cosplay for a living either.
The people in the Otaku category are the ones who are a little too obsessed with anime. They're like the Hyper-Fan. They love the culture, as it's probably clear once you listen to their music or go into their bedrooms, and they feel deeply connected with certain characters in certain animes. These are the ones that y'all tend to notice and get weirded out by. They're the ones that will start singing the Pokemon theme song at the top of their lungs. They also are very passionate about anime and the community, including the voice actors, and they tend to follow a lot of the latest news in the Anime industry world. They can be a bit elitist, but they're not as bad as the weeaboos. They're not the most social creatures out there, but they mean well. Usually. These are your typical convention attendees. (Otaku isn't even a compliment, even though they call themselves that. In Japan, it's apparently a major insult. Basically means you're a hermit loser freak. Irony at its finest.)
...Then you got Weeaboos. Basically... They're the ones who are guilty of culture appropriation. Now, these motherfukkers are the ones that you can't say shyt around, because they will get mad as hell if you have a different opinion than them. Ever heard someone say "This character is so kawaii but I HATE who she loves, because he's such a baka, he already has another waifu!"? That's them. They dislike their own culture and would rather live in Japan, even though the only reason why they'd want to go there is due to the anime and usually not for the culture of Japan in itself. They completely submerge themselves in strictly Japanese entertainment. Any anime comes out? They'd rather watch the subs over dubs. Every time. They're elitist like crazy. They make every other category look bad. And they're the ones at conventions that go a little too hard in the paint (or in this case, the pocky..) and cause trouble/don't shower.
--------------------------------------------------------------
Once again, it ain't exclusive, but from my experiences... this is usually how it goes.