To me, it has honestly just become another buzzword. It gets slapped onto, essentially, any group of people associated with a project - as if (A) labeling it a "community" means that the event/product provider actually cares about, listens to, and engages with its consumers or fans, or (B) the consumers/fans actually know and cooperatively interact with each other. Of course, those are both very often not the case.
Originally, I think the word had the meaning of "tight-knit group of people", and then "group of people who work together or actively interact with each other" - which would describe things like in-person cultural neighborhoods, websites for specific interests (e.g. specific fanfiction interests, modding forums for specific projects for specific games), or activist groups.
So, generally, the word evokes negative feelings from me, because I always suspect it of being used as another empty PR word.
If you're asking what I think composes a community, or what activities a community engages in - that's a different question, and it depends on how you're defining community re: the descriptions above.