You can think of episodes as emails in which your friend send you a link which points to a voice file, such as MP3 along with short description, title explaing that voice file. In reality episodes consists of following major parts:
Title of the content, as in the case of emails
Explaining what that episode is about.
When that episode is published
Associated web page address
Where you can find more information about that episode or where the content is related about
Web address of the voice file
From where programs like Ziepod can locate that voice message and enables you to play and download it.
Other than listed parts above, it may also contain information about who wrote that and its assigned categories(labels) in order to provide extra information about the content to categories the episode easily.
To learn more about how to manage episodes insize Ziepod, check out related help topics listed below.