That means they are running non-free code, which seems to be one of their main points against Github.
It's community edition.
The community edition doesn't have any tiers or features, those are only in the Enterprise Edition.
This requires asking for a specific number of license seats for your open source project and that's impossible to work with. Every possible user account/contributor takes up a license. How many contributors will I have tomorrow? Don't know. How many spam accounts will I have that waste license seats? Too many, and they're impossible to clean up.