If you choose to create your own circles, you will decide between a Public, Limited, and Private circle.
---> Public Circles: Are viewable by anyone, and anyone can join on their own.
---> Limited Circles: Are viewable by anyone, but the Administrator needs to accept new members before they join.
---> Private Circles: Are viewable only by the members in the circle, and all members must be invited by the Administrator.
Watch Video: Scott & Matias talk about using "circles" in the Behance Network