The Subtitle slide is a particular kind of Player slide that allows you to input subtitles over a video. The process for creating and inputting video is described in some detail in this article.
If you don't input any text on the Subtitle slide it will behave exactly as a Player slide, the only difference between them then is that the default audio behavior is different: The Subtitle slide defaults to "Mute music" and the "Player slide to "No change", since it would make little to no sense subtitling a silent video clip. (Although you could use the Subtitle slide to add the nameplate functionality for attribution even when having a video without subtitles.)
Behavior and usage
The Subtitle slide holds four different text fields, the two Subtitle lines and the Name and Title that make up the nameplate. All these fields are pretty self-explanatory.
You can style the subtitles with either a drop shadow or a backplate. And you can also change the text color of either line into yellow. This is useful when more than one person is talking, and you want to, for example, show what a question is and what is an answer when the video does not indicate that. These settings reside under "Color settings," where you also can change all colors for the nameplate.
You can position your background asset with the X- and Y-position dropdowns, which will come in handy when fitting video into other formats than the video's original. You can also use a still image in a Subtitle slide, and then the Scale and Wiggle settings will also have an impact on how the background behaves.
When using a still image, the default length will be five seconds but you can of course change that as needed.