Podcast content spans a wide range of topics including health & nutrition, bio-hacking, entrepreneurship, personal development, daily news, comedy, entertainment, music of virtually every genre, and much more.  Podcasts are generally presented by a host who is an expert in his or her field and provides monthly, weekly, or even daily episodes that can be streamed, downloaded a la carte, or automatically pushed to your device(s) once you subscribe to them.  The episode format varies widely from genre to genre, host to host, and even episode to episode.  This variety is growing and is exactly why I consume so many podcasts regularly, and a big part of why their popularity is quickly rising.