The Changing Tides of Social Networking
Fundamentally, Google+ is a social network that has been built from the ground up around the concept of Circles, Hangouts and Sparks. Each circle, which you define, is a group of contacts, friends, acquaintances, and/or family that you categorize in a certain way. The benefit of this system, as compared to Facebook or LinkedIn, is that it enables you to share information that is specific to each circle.
Using Hangouts, you can real-time chat and video conference with those in Circles and Sparks brings the power of Google's information aggregation capability to the serve your interests.
Detailed Information: Google+ (Plus) for Businesses, Publishers and Bloggers