Well for starters this is to differentiate the otaku and weeb, for me the two are just different in their own ways and other's understanding. This article is all about my understanding and I'm willing to share to you guys.
Well for my understanding Otaku means that a person is deeply consumed by their interests in pop culture such as Anime and other stuffs. It can also be compared to the western term geek or nerd. example of that is like a romance anime or comedy anime where the MC tends to be a shut-in type but when time passes he/she became successful in life or he/she is on to new leaf of life.
Well, although otaku already existed in some Japanese circles, It is very popular around the world not only in Japan and other SEA countries but also on the other continents as well. For the west being otaku means a die hard anime lover or fan, before you become an otaku you need to watch enough anime and read enough manga to be one.
On the other hand, lets talk about wee, On what I understand about being weeb is that, it is almost the same as being otaku but slightly different because it is referring to a non-Japanese person who loves aspects of the country's culture so much that they're pretend and wishing they were Japanese. Weeb or Weeaboo implies a full-blown addiction or obnoxiousness to the point that, that person is disrespecting others.
Today, Being Otaku in the East or West is just as often taken as a label to be proudly worn. (just like me :">) Otaku for me in short is that "WE LOVE ANIME" or anime lover or anime fan. And that's all of my understanding about the two, Thank you :D