On the internet, it's hard to make sure the account owner's social media is really the person, especially if he is a famous person. Verification system was used to ensure the authenticity of an account really belongs to the people concerned.
"We started issuing verification badge on your profile so you can be sure the people you add to the circle is really them," said the Ai Wen Yu, staff at Google+, as quoted from PCWorld, Sunday (08/21/2011).
Initially, Google+'s focus verify famous people or those that are added in many circles. Verification mark will appear next to users of Google + celebrity names. Next, verify option will be visited more people
Circles itself is an element in Google + where users can group their contacts. For example group work or group of friends of friends.