Functionally, Google+ is described as Facebook meets Twitter with a dash of Tumblr. Its most prominent feature is Circles, which are similar to friend lists on Twitter, LiveJournal, and Facebook, and is the backbone of "adding" users on Google+. You don't send a friend request to someone you want to share content with; you simply add them to one or more of your Circles, and whether or not they do the same with you is up to them.
Circles can be used to organize groups of friends, but more importantly, when making posts, you control which Circles to make your posts visible to, on a per-post basis and which Circles can see which elements of your profile. Ideally, this allows one to add, say, coworkers, family, and classmates, yet still be able to use their account to make posts hidden from these people. If this sounds familiar, yes, Facebook has these features too, though Google+ makes these features one of their main features rather than as something in the background.
Unusually for a social networking site, Google+ allows basic text formatting in posts, and, much to the joy of many users, a post-editing feature.
On October 2018, it was discovered that a security vulnerability could have exposed the personal information of over half a million of its users. Google soon announced that it was shutting down this service, citing its low popularity, and it was shut down on April 2, 2019.
Google+ has examples of:
- Call a Rabbit a "Smeerp":
- Friend lists = "Circles"
- Adding people = "Circling"
- Liking / Favoriting a post or comment = "+1" (Although the term's been around for a while, Google chose to adapt this as the name of the "like" feature.)
- Voice and video chat = "Hangout"
- Mobile messaging = "Huddle" (Although it was renamed to the more conventional "Messaging" in September 2011)
- I Know Your True Name: Google+ requires that users go by their real names online, with suspected violators having their accounts terminated. This was later relaxed to a 4-day grace period. Regardless, the forcing of users to go by their real names caused quite the controversy among those concerned for their privacy. Averted once Google loosened up the requirement.
- Meaningful Name: Google+ profiles are designed after profiles on Google Profiles, making G+ essentially an enhanced version of Profiles and hence its name.
- Unwanted Assistance: Google kept wanting to push Google+ on every user, to the annoyance of many YouTube users. This usually came in the form of "helpful" pop-up bubbles "offering" to set up a Google+ account, no matter how many times users declined.