Otaku means home or family or in Japanese slang means people with obsessive interests in Anime, Manga, and Video Games.
Weeaboos or Wapanese - Slang term for Japanese wannabes that carry it to the extreme. They go way beyond Otaku's with Japanese sub-culture. Weeaboos will sometimes refer to themselves as Wapanese.
If you've spent anytime at Anime or Otaku Conventions or at Anime & Manga sites on the internet you will come across plenty of Otaku's and Weeaboos/Wapanese. Please do not get them confused they are completely different. Which is why I made this post.
Both love Anime, Manga, and Video Games.
Otaku's love Anime/Manga/Video Games , but realize there is more to Japan than just Anime, Manga, and Video Games.
Weeaboos or Wapanese pretty much think Japan is nothing but Anime, Manga, and Video Games.
Otaku's can be from Japan or anywhere in the world. If a Otaku isn't from Japan they may try to learn Japanese but don't profess they know Japanese fluently.
Weeaboos or Wapanese are not from Japan and will claim they can speak Japanese but don't really know hardly any Japanese.
Otaku's will dress as their favotite Anime & Manga characters at only Anime & Manga Conventions. Otaku's do not dress in drag or cross dress.
Weeaboos or Wapanese are known for dressing as their favotite Anime & Manga characters when ever they feel like. Even dressing as their favotite Anime & Manga character even if it's the opposite sex.
Some Otaku girls refer to themselves as Otakueets.
It is a misconception that Otaku girls only go for guys who act girlish. This simply isn't true.
It is actually Weeaboos or Wapanese girls that usually go for guys who act girlish.
Both eat Pocky but Otaku's don't obsess over it.
Both use the same Japanese slang like
Kawaii = cute
Baka = stupid
Most but not all Weeaboos or Wapanese are gay or lesbian and into Yaoi or Yuri.
Otaku's are least likely to be into Yaoi or Yuri.
Both can be into Ecchi or Hentai (Anime & Manga porn) or not.
Both are into J-POP and J-ROCK.
Weeaboos or Wapanese will think Japan is better than their own country. Even though 95% of them never been to Japan.
Otaku's do not think like this unless they are Japanese. Then of course they'll love their country.
In short Weeaboos or Wapanese is a obsessive fad and Otaku is a hobby.