What Is RSS?
Depending on whom you ask RSS stands for 'Really Simple Syndication' or 'Rich Site Summary'. It provides you with an abridged or shortened version of a site’s content keeping you up to date with news and information that you have subscribed to. It also saves you time browsing or searching for information on websites. Now the content you want can be delivered directly to your RSS reader without the need for e-mail’s and sifting through the millions of webpages on the internet. This content is called a "feed."
The Language RSS uses to do this is xml which is perfect for the transfer of small tailored information over the internet.
What Is a Podcast?
A ‘podcast’ is an audio broadcast aimed at internet users. iTunes were pioneers of the podcast thus their popular iPod player lent the format its name. A podcast is typically in the MP3 format and is syndicated by being attached to an RSS feed. This gives it a major advantage over common audio files on the internet because it gives the user the choice to have the podcast come to them rather than the user having to search through the net for what he/she wants to listen to. The content of a podcast is typically updated information or news and serves much the same purpose as an RSS feed.
How do I listen to a podcast?
Once downloaded via an RSS feed the podcast can be added to any MP3 or iPod and can be listened to at the user’s convenience, much better than having to plan your day round your favourite radio show, documentary or news broadcast.
Can I listen on my iPod?
iTunes provide an excellent facility for searching and posting podcasts. They allow users to comment, review and rate the latest podcast offerings so you will easily be able to find something to suit your needs. Transferring a podcast to an iPod or MP3 player is exactly the same as uploading you favourite music track, so no technical nightmares.
References
iTunes - Podcast Guide
RSS - Wikipedia
How to Put Video Podcast on iPod with iTunes