In each episode, you'll find several options when finalizing changes: Delete, Cancel, Save, and Publish. Saving will update the text and settings of the feed without changing availability, while publishing will add the episode to the feed for listeners.
Each option performs the following, from right to left:
Publish Episode: This makes the audio content and show notes available to listeners, as you see it in that episode page of your account. Once published, this option changes to Unpublish, which will remove the episode from the feed for all listeners.
Save & Return: This doesn't change the availability of the episode for any listeners, but saves any changes you've made to show notes or titles. If the episode is published, the listeners will see those changes to the feed in their podcast apps. It returns back to the feed page.
Cancel & Return: Any changes you've made to the text or episode settings will be undone and reverted back to what they were before.
Delete Episode: The episode will be removed from all listeners feeds and removed from inside your account. This cannot be undone.