Here are some terms used in the Solo Graphics feature that might help you understand the system a bit better:
Composition: this is a template, essentially. Its both the graphical design of the graphics themselves as well as a list of possible elements you can pick from. Once you pick a composition to start from, and start to actually edit the text and logos that will appear in each playlist, that is called a Playlist.
Playlist: A playlist start from a composition but then you start to customize it by building up a play order and editing text, images and sometimes colors - this new entity is called a Playlist. Each time you apply graphics you can start from a Playlist or start fresh from a Composition.
Engine: the engine is the resource in the cloud that renders your graphics into your video stream. Each new stream requires an engine. For the most part, Solo Portal will start and stop the engine for you, this is why its important to start the stream from the solo portal, rather then from the unit. In some rare or problem cases, the engine may still be running when your stream has stopped (maybe your batteries ran out!), and these cases an override link of Stop Engine is provided on the dashboard to stop the resource at any time.
Lower Third, Lower Line, Lower Topic, etc: a common graphic element in TV, you have seen it hundreds of times! Its a bar and text that appears in the lower 1/3 of the screen, providing information - such as a name, place, or topic. Depending on exact positioning and format it can have a few names but the idea is almost always the same.
OTS: Stands for "Over the Shoulder" and is another common element you see in many news casts. Its a graphic, often an image with text, that seems to appear over the host's shoulder, hence the name!
Bug: In the Solo Graphics system sometimes called Upper Right, its any element that stays on the screen for a long time. Examples include a line notting this broadcast is live, noting the location, or maybe providing your shows social media handle.