Q) What's a podcast? A) Typically, a free audio program ranging from 5min to 3hrs. Podcasts are generally free to download and can be listened to at any time. The subjects and formats that podcasts span are virtually limitless. There's podcasts about medicine, sport, comedy, movies, gaming; Anything really.
Q) Where do I find them? A) Apple iTunes has a podcast store (don't worry, 99% are free) where you can find them. Other popular places include Podbay, Stitcher and TuneIn.
Q) How do I listen to them? Popular free apps are Apple's Podcast for iPhones and Podcast Player for Android. Pocketcasts costs a few dollars but is a great app for iOS and Android.