Google Plus Hangouts allow you and nine others to simultaneously video conference. Each person has the option of using either video, voice, or text chat, and everyone can interact all at once. An eleventh person trying to join the conversation would find that the hangout was full. The only way for an eleventh member to join a hangout is after someone else has left it.
What happens when you're a very popular person and need more than nine attendees? What if you need hundreds or thousands of attendees? That's where Google Plus Hangouts on the Air comes in. Rather than allowing only ten simultaneous chatters to view anything, a hangout on the air allows nine people to join the hangout and everyone else to view it.
Here's how it works:
The first person starts the hangout.
Nine other people can join it normally.
Everyone else gets to see the hangout live on YouTube, but they don't get to interact with it.
That means rock stars, gurus, panels of experts, and politicians can all have their massively large conversation without filling the screen with ten thousand simultaneous video chatters. Everyone gets to see the show, but only a select few get the front row seats. You can also still comment on the post in the thread announcing a hangout, so while the speaker wouldn't necessarily always see your question, it's possible to interact with others who are viewing the hangout at the same time as you are.
Once your hangout is over, the session is still available as a YouTube video, which can be made either private or public. That means you could have a panel discussion or start your own Internet-based weekly show and have the sessions available for later audiences to view.
Who can start a Hangout on the Air?
Right now (January 2012) Google has to specifically invite you. The product is still in beta. This is like becoming a Partner Channel on YouTube or being listed in the Google+ directory of suggested users. However, this could potentially end up being a feature in regular Google Plus hangouts. It could potentially be useful for things like board meetings or distance learning classrooms.
The original version required Google programmers to set up a time and place for official hangouts, making them big productions. Now a person who's account has been "blessed" with the on air hangout ability could set one up whenever they wish. Google is undoubtedly hoping this adds to the popularity of Google Plus, but I'm hoping this sort of activity could be used to create a new type of broadcasting.
The White House also announced a January 30, 2012 hangout.
