RSS stands for Rich Site Summary, Really Simple Syndication or Real-time Simple Syndication. It is a way to get frequently changing information from websites (blog posts, audio and video, podcasts!). RSS feeds enable publishers to syndicate data automatically. In the case of podcasts, your RSS feed is what you need to submit to iTunes and other podcatchers/directories. These sites do not actually host your content, but instead use your RSS feed to get your latest content.
Podcast hosting platforms such as Podbean can provide a working RSS feed for your podcast and provide you simple tools for pushing your content out to iTunes and other destinations. You can also create your own RSS feed if you self-host. Before submitting to iTunes, make sure to check your feed with a feed validation service to make sure you don’t run into any problems.
Read more about how to get your podcast on iTunes.