Within my personal realm, I have used the term "sphere" to describe a set of websites and "communities" (I put it in quotes because I don't think real communities can be virtual; I'm using the word how many internet-goers use it) on the internet or a set of locations and communities in real life that focus on a very specific supposed (whether or not the people involved actually have the qualities) quality of the people involved as if (whether or not it actually is) the quality is a very important and significant quality. An example is the "autism-sphere." It's members focus on their autism to a great extent, often writing tens of thousands of words about the subject and dedicating entire blogs and websites to it. They put extreme focus on their autism.