Short definition: A podcast is a recurring program delivered over the internet. They don't always have to be audio (we support video podcasts, too), but most are audio-based conversations.
Podcasts span all topics — from technology news to business to fashion trends. Anyone can create them, from an individual barking passionate opinions at their phone to a global news organization working in a professional studio.
People sometimes use "podcast" to refer to an individual show or a whole series of shows, so where possible, we use the terms "series" and "episode" to make the distinction clear.