How the subscription process works when user subscribe to podcast ( i have created audio podcast on mac-iTunes)? Also Is there any different process to create Audio podcast app on iphone ??

I created audio Podcast and working fine now with iTunes(Subscribe to podcast) On Mac-itunes. Could you tell me how the Subscription process works when user subscribe to audio or should be implemented ?

And also want to know ,Is there any different process to create audio Podcast application for iphone ?Please Clarify both (podcast in mac and iphone ) , i am confused ?