I've been using "forum" as a generic word to refer to any of β
- Lemmy "communities"
- Kbin "magazines"
- Reddit "subreddits"
- ... and so on.
In all these cases, a forum has similar attributes:
- It is a container for posts.
- Users can subscribe to it.
- It has its own moderation team.
- It can have its own policies.
This is pretty generic. So what isn't a forum in this sense?
A Twitter hashtag isn't a forum. Although it can be used to find posts, and users can follow it, it does not have its own moderation team or policies.
A Gmail account isn't a forum. It receives messages. It has its own "moderator": you, the account owner, can delete messages from your inbox without needing to go through Gmail's admins. It can have its own "policies": you can write spam-filtering rules. But other people can't subscribe to it.
A blog without comments isn't a forum. It is a container for posts, and users can subscribe to it (e.g. via RSS, or just bookmarking), but it doesn't have moderation or policies because there's nothing to moderate: the blogger is the only one posting there.