I don't know if I'm more concerned about your lack of knowing what a Podcast is or the fact that googling it would be pretty easy: http://lmgtfy.com/?q=podcast
Seriously though, a podcast is just an episodic series (usually audio based) that could be on a wide range of topics. They are basically streaming audio files to your smartphone or computer that you can subscribe to whenever new episodes pop up. Think of them as very specific Internet radio talk shows.