A Schedulable Zone allows you to create a space within a Layout for you to publish one or a number of Playlists into.
When you create a Schedulable Zone, you can configure its basic properties, but you essentially leave the zone empty whilst creating a Layout, ready to be populated during the Publish Process.
You can learn more about this by reading this article
You can learn more about creating Layouts by watching the Introduction to the Layout Designer video, below:
You can also learn more about Schedulable Zones in the following videos:
What will happen if I don’t Publish any content within a Schedulable zone?
By default, if a Schedulable zone is left empty during the Publish process, it will remain empty and show the area beneath (ie. the background colour or image of a Layout). However, you are able to set a Default Asset within a Schedulable Zone.
A Default Asset allows you to set a sort of screensaver for if this particular zone is left empty. This can be any single asset, ie. an image, video, web page or widget from your Asset Library.