On my iPhone 5 with ios 7 I can choose to automatically download "all" episodes or "most recent". At first glance it sounds obvious what the difference is, but since I've had the "all" setting checked for a while on a podcast that has not started auto downloading (I have enough free space) I have to ask. The app has had plenty of wifi access. The podcast has some added but not downloaded episodes.
Auto downloading the most recent episode only makes sense if it keeps downloading the most recent episode at all points in time from then on. So basically that's the same as "most recent and all future episodes". The "all" setting should then download everything, but what is confusing in that case is that as an explanation of the auto-download settings it says "automatically download new episodes". So is the "all" option "all future episodes" or what? If so there's almost no difference between the two settings.
Best Answer
From my experience, the Podcast.ipa will stop downloading podcasts if you haven't listened to several recent ones. It will update the list to say that they are there but it will not download them unless, I think, the most recent 3-5 episodes have been placed.
"Most Recent" in the context of Podcast.ipa means it will keep the 3 most recent episodes on your iOS device. It will still sync/save where you last listed to previous episodes but it removes it to conserve space. If you have all selected it will download the most current one and update in the future while retaining all episodes that it/you has/have downloaded until you "physically" delete it from the list/device.
But I too have noticed an issue with the last couple versions of the Podcast.ipa where it doesn't download even though I am subscribed and it is set to download "All" I think this is bug at this point in time and hope that they fix it soon. (http://www.apple.com/feedback/iphone.html)