Say you have two monitors, one 16:9 mounted normally and one 16:9 mounted vertically. You can define a single Show to display the same content (more or less), but you can (and should) define 2 layouts to show it differently! Take a look at this example:
Here, the same content is shown, but it is layed out differently. The same goes when you have different monitors with different aspect ratios (Don't know what "aspect ratio" is? Check the end of this article.) You can create two different layouts in a Show that will match the aspect ratio of each monitor, so that content is reproduced better in each monitor and fills it completely.
When you create (or edit) a Show in Yodeck, you can add more layouts by clicking the [+] button right above the layout editor.
The menu that appears provide you with all options: 16:9, 16:10, 4:3, 5:3, 5:4, 3:2, 17:9, both for horizontal and vertical layouts. You just select a new ratio or orientation, and a new empty editor appears, allowing you to add more content for that type of monitor.
Yodeck Players receive all layouts for the Show they must playback. Each Player know the resolution of the monitor currently connected to it, along with the "Rotated" attribute set to it through Yodeck. In the Monitor details, you can set each monitor to be rotated.
So, each Monitor will automatically show the best possible view.
What is an Aspect Ratio?
Aspect ratio is the fraction that indicates the shape of your monitor. Every monitor has a resolution in pixels (e.g. 1920x1080), so dividing the two numbers gives you the aspect ratio (in this case, it's 16:9, equal to about 1.777777). There are different monitors out there, with a variety of aspect ratios.
The standard aspect ratio for most screens and TVs is 16:9. That includes "HD Ready", "Full HD" and "4K" (or "UltraHD") TVs and monitors. So, when you create a new layout in Yodeck, you are presented with a 16:9 editor to create your layout.