YouTube Live is a feature enabled for select YouTube Live Streaming channel Partners. Google Hangouts on Air is enabled for anyone with a Google+ account and YouTube channel.
There are some big difference between the two. As of this post here are some of them:
- A Hangouts on Air (HoA) event is a different appearance and layout of the video - there is a white background, a large main video of who is speaking, up to 9 other G+ members video frames seen on the lower third, and a Google+ bug on the top left corner.
- Hangouts on Air, if listed as public, can be seen on the YouTube.com/Live home page under 'Live Now' and 'Recently Broadcasted'.
- Hangouts on Air are not promoted under 'Next 24 hours' or 'Next 7 days'
- HoA stream at lower bitrates and resolution than YouTube Live streaming.
The two features can be used together and especially useful for remote interviews. The Live Streaming Partner sets up a live event and another G+ member, with a YouTube channel, sets up a separate HoA event. The Live Streaming Partner can take the HoA source and switch into the live stream. Check out HuffPostLive exclusive use of Hangouts on Air.
Here is the YouTube support description of the two features:
How can I live stream a Google+ Hangout on my YouTube channel?
Hangouts on Air and YouTube Live are two separate features. Hangouts on Air enables you to live stream your Google+ Hangout on your YouTube channel. Anyone with a Google+ profile and a YouTube channel in good standing will be able to use Hangouts on Air.
Visit the Hangouts on Air help center for more information about Google+ Hangouts and Hangouts on Air.
More information about Hangouts on Air can be found here:
More information about streaming your event live on YouTube can be found by contacting LiveEventsChannel@mxpi.com