Google+

Google+ is a social networking website launched in 2011 as a competitor to Facebook and Twitter. The pilot phase of the project gained users on an invitation-only basis in June 2011 but the site opened to all that September. The site includes various new features and incorporates two existing Google services, Google Profiles and Google Buzz, the latter being the search engine giant's previous attempt at developing a social networking site.

Google+ is similar to Facebook in that people can invite and add people to follow their social and everyday activities, though unlike Facebook, individuals need not add the inviter to their own list of approved 'friends' in return to see updates. Groups of people are permitted to view such updates according to the 'Circles' that the inviter has placed them. All linked accounts must be added to at least one Circle; in contrast, Facebook's 'friend' lists are optional. Google+ also overlaps with Twitter in that a user can link to public figures or people they do not know by adding them to their Circles, in the same way that Twitter users can 'follow' anyone whose page is publicly accessible. Google+, however, allows much lengthier posts than the quick 'tweets' of up to 140 characters found on Twitter. In October 2011, Google+ introduced support for hashtags, which work similarly to the feature originally introduced on Twitter.