Also called "team chat" and currently most exemplified by Discord and Slack, sometimes Matrix and IRC.
Levels
There are different kinds of community chat space.
- 4 friends talk, mostly one thread, often silent. Group text
 - Totally private family or friends or company. At some size multiple common topics or uses can emerge, threads are more common
 - Invite only / approval only fully private. A club. Existence is public, logs may or may not be, but you gotta be approved to get in.
 - Public community
 
Features
- Long archive retention
 - Full text archive search or better
 - Ask for voice and/or apply for membership in a channel or server
 - Related topic spaces (multiple channel or durable threads or something)
 
