Google introduced Buzz in February 2010 and it will be killed off for Google+.
Google Buzz makes Gmail social by letting users view media and status updates shared online by their friends. This format is popular with Facebook and Twitter. Status update through Buzz is not limited to 140 characters.
From Google Blog: Changing the world takes focus on the future, and honesty about the past. We learned a lot from products like Buzz, and are putting that learning to work every day in our vision for products like Google+. Our users expect great things from us; today’s announcements let us focus even more on giving them something truly awesome.