There are three different episode types you can choose from:
A regular podcast episode.
In a trailer episode you explain to your listeners why your podcast is special and why they should definitely subscribe to it. The trailer should introduce your content in an entertaining way and make them want to hear more. In addition, it is displayed on the various podcast sites before the first episode and is therefore an important tool for a podcast that you are launching in order to be found on all desired podcast platforms in time for the release of the first episode. Why the trailer is an important thing: LINK
A special episode that doesn't fit into the pattern of your normal podcast. Maybe you have a special "outtakes" episode or an episode in which you talk about a topic which your podcast doesn't normally deal with. You can mark such an episode as Extra.