Hosts have access to a wide variety of tools during a live event to control what the audience sees. We refer to these as host controls. We also refer to what the audience sees as the stage. Anyone whose camera or screen share is visible is considered on stage.
By default, anyone in the broadcast is on stage. In the screenshot below, there are 2 people on stage.
Focusing a screen
Clicking on the "Focus screen" icon will minimize the others streams to the top left corner of the video feed. To unfocus a screen, simply click on the "Unfocus screen" icon.
Removing a screen
You can permanently remove a screen by clicking on the "Remove screen" icon.
Toggle audio / video
The "Toggle audio" and "Toggle video" icons respectively mute and turn a camera on / off. It is important to note that a video turned off will not appear in the recording.