If you still want to know more about what Steem Communities check out 
But without further delay like to bring out my newest community called the Introduce Yourself Community here:
So if you are new here drop a "Hi" in there to meet other Steemians!
This is all part of a much bigger picture being put together and will be a two-pronged approach as this can also be used in the User Help community here:
This community will have a group of helpers who will answer questions from people who need help on Steem. Join if you are ok with answering questions from future noobs and I'll eventually give you a "role" reflecting it.
What we don't see yet is the future addition of SMTs which is Steem's smart tokens. I believe it will play an integral role with communities and as we go along for the user help community we'll be able to reward our mods/helps in with Steem or our own SMT token. It helps make it worth their time to help people out.
This will come out of sort of a "mini-reward pool" inside the community itself. Rewards will be dished out based on the aggregate total post rewards in the community with a % going to mods. It will be interesting to see what features are added in the future.
We are just at the start of all this taking shape so the time is now to jump in!
P.S
If you want to follow my owner personal community you can here:
I'll be introducing future communities I build through it.
