It is similar to LinkedIn Groups and Facebook Groups but of-course integrated into Google +.
Before you create a community, look at other communities and consider joining a few to see what you find useful. When you click on the "Community" on the left side after signing in on Google+ you will see the word "Discover communities" and to the right is a search window to look up your interest. Here is one I created for people with a passion for discussing the technology of creating Podcasts:
A Google Plus business page or individual can create a community page. You can make the page public or Private. Information about the 4 different types of Google Communities can be found here:
More information about Google Communities can be found here:
An example of a use of communities is: Anora McGaha and I set up a private community for participants of Social Media Manager Certificate program to discuss the class, share their projects and where we have resources links that will be used in the class. This group is not listed and is on a by invitation only basis.
A few points:
Here is a short video I built on creating a private Google+ Community:
This is just an intro and I would love to hear how you are using Google+ Communities.
Feel free to connect to me personally on Google Plus at: http://BrossmanONGP.com
Martin Brossman - ProNetworkingOnLine.com