google plus circles

Many of my friends is asking me that what is google circle and what is google plus so i have posted this post.
"circles" groups your friends together

Google circles are group of  friends which you have organized by topics like friends, family , college , buddies , roommates , classmates.

how to use google circles
suppose you have 3 circles named family , classmates and friends
now if you want to add a person in family circle then you need to click on that person and just simply drage him/her into family circle at that time in green background one +1 is popup .
Now if you want to remove person from family and you want to add him/her into friends then find that person in family group and and simply click on it and drag it in friends circle. Then the person will deleted from family circle and it will be added in friends circle.