What is needed to start a podcast?

Every podcast needs:

• A web server to host MP3 files,

• A way to create new episodes, and add show notes,

• A way to publish new episodes, and update the podcast's RSS feed,

• And a way to generate a valid RSS feed.

Podcast apps like Apple Podcasts and Pocket Casts are podcast players but they're not hosting platforms. When you click "download" or "subscribe" in these apps, the request gets sent to whichever host your favorite podcast is using (like Transistor.fm). The podcast player will then download the MP3 file from that server.