The broadcasting feature allows you, your speakers, and community managers to speak to the entire room. During a broadcast, all group conversations are being paused and only the broadcaster(s) are visible and audible. To give your guests a chance to end their conversations, there is a countdown before the broadcast starts.
You can also use the screen sharing feature in the broadcast mode. Up to 6 people can join a broadcast simultaneously - all of them must have authenticated themselves as a host first.
This works very well for welcomings, presentations, or panel discussions. Also, event organizers like to use it to moderate the crowd during the mingling phase.