Google+ is 4 years old already!

The Google+ Project or Google Circles launched on 28th June, 2011.

Google+ is an essential part of my business, with other Google tools.

They've come a long way since.
From the official Google blog announcing the launch, written by +Vic Gundotra:

+You: putting you first, all across Google

That’s the Google+ project so far: Circles, Sparks, Hangouts and mobile. We’re beginning in Field Trial, so you may find some rough edges, and the project is by invitation only. But online sharing needs a serious re-think, so it’s time we got started. There’s just one more thing—really the only thing: You.

Google+ Business Pages Updates

Google is improving the user experience for business pages, check out these desktop updates!
Even better visibility and stats for business pages along with a nicer UX...

Learn more about what Google+ can offer to you and your business: Google+ My Business Help Center

Google Business pages

Google+ pages provides businesses, products, brands, and organizations with a public identity and presence on Google+.  You can also create a Page for your band, pet, fan club, sports team, kid's camp, event or anything that is not against the Google Terms of Service - or user rules and principles.  For simplicity's sake I'll go on writing about "your business".

Google+ pages interact in the Google+ world similar to the way that regular Google+ profile owners do - they can add people to circles, edit their profile, share things in Google+, +1 comments and photos, and create and join Hangouts and Communities.
But they’re not entirely the same, especially since this update.