Studio's Speaker view consists of four main sections, the view layout tabs, your primary viewport, the speaker controls, and the speaker chat.
Across the top of the Speaker view are your different view layouts. Clicking on one of the layouts will switch to that view layout. More info
Next is your primary viewport, while the way this looks can change depending on your selected view layout, it will always include a preview of your own video to the left and the live program. If any view other than the "Stage" view layout is selected, it will appear to the left with your video.
The last area which appears below the Speaker controls is the Chat. This allows you to communicate backstage with other speakers or the host. You can also share files and documents on the chat by clicking on the (+) button and hitting enter/ return after selecting the file(s).