Your draft is your working copy: where you add all the titles, tags, descriptions and attach your audio. At this stage the episode is still private.
Your scheduled episode is published and waiting for its assigned debut date, when it will become available to the public. At this point it is still private and will not appear in podcast apps.
Your episode is available in your feed, or it soon will be. You can make edits to a published episode by clicking “edit” and saving all changes. And you'll now be able to track metrics for the episode. Voila!