Explanation:

Box 1: Organizer
Invite attendees
Live Event Roles and Responsibilities
Event organizers can invite others to the event and grant them one of two roles: Producer or Presenter. Both roles have different access and responsibilities for the Live Event. You can have multiple producers and presenters (up to 250, though only the last 10 who have spoken will appear in the producer view list).
Box 2: Presenter
Moderate Q&A
Presenter Capabilities
Please see Microsoft's documentation for additional details on presenter capabilities.
Share video, your screen, or other content that the producer can then send to the Live Event Sharing of computer audio in a Live Event is current only support on the Windows client of MS Teams.
Mute other presenters
Chat with other producers and presenters
Moderate Q&A
Manage the event recording and reports
Box 3: Producer
Start and stop the live event
Producers
Producers have access and control over nearly all settings and details for an event. However, especially in larger Live Events, a producer tends to have the more supportive role of managing which video feeds, shared screens, or other content is presented in the event.
Consider limiting the number of producers for your event. Not only is the producer interface more complex than the presenter's, but having more producers than needed can make coordination more difficult.
Producer Capabilities
Please see Microsoft's documentation for additional details on producer capabilities.
Select video feeds or other content shared by presenters or producers and send them to the event Mute presenters or producers individually or collectively Chat with other producers and presenters Start and end the Live Event Moderate Q&A Manage the event recording and reports Reference:
https://www.uvm.edu/it/kb/article/teams-live-events/