ProPresenter's output is divided up into 6 layers where content can play back. These layers stack up to create the final output that the audience sees. Many times you will only be using one or two of these layers, and some times one layer will completely cover one or more layers below it; it is normal for these things to happen in the course of running ProPresenter.
Here is a quick breakout of the different Layers of ProPresenter:
A Mask is a layer that hides everything behind it. Let’s say you need to project onto a circle screen or a really narrow screen, you could use a mask to black out everything outside the shape of your screen. Once a Mask is enabled, it stays active over the output as long as ProPresenter is open. You can create simple masks in ProPresenter or you can use editing software to create more complex masks and load them as .png files with transparency.
The Props Layer actually contains two different elements. The Props feature can be used to add text or images over top of your content, like a TV channel logo. Messages are also shown on the Props Layer.
The Slide Layer includes everything you can add to a slide within the Editor. This is also the layer where Social Media, PowerPoint/Keynote files, and other similar content is shown.
This is the layer where Backgrounds and Foregrounds (including still images and motions/videos) are shown.
The Live Video layer uses the camera that you have selected in Preferences. It is also where the video input from the Alpha Keyer Module will be shown. If you are using live video without the Module, then your video source is cleared by Foregrounds or Clear commands. If you are live video with the Module, then the video input will always be live behind the rest of your content.
This is the default color that you have set in Preferences on the Display tab. It’s the color shown when nothing else is on screen.