For the listener:
For listeners, podcasts are like radio shows recorded on a DVR. They don't have to listen to them when they happen, but download them to listen to them later, at their own convenience.
For the maker:
Everyday entertainment used to be entirely broadcast, but due to technology, broadcasting is being replaced by podcasting. The reason, simply put, is cost. It costs a ton to have a studio, to create content, and to broadcast it either through the air, or via cable. But podcasting doesn't have this capital heavy drawback.
It costs nothing for the software to make podcasts, there are many places where you can upload your files for free, and you can distribute them at no cost through iTunes, or various feed readers.
Making a podcast is super. You can do it in bits and pieces and stitch it together. For example, you might record your poems, and send the audio file to me. I might record an interview, and someone else sends me a recording of heir short story. I take these files, pop them into the show template in my audio program, then I write a little monologue to go with the bits, record that, and voila! A podcast is done.
Podcasts are actually perfect for people who are creative and engaged, but have busy, disparate schedules that would make ever meeting in the same time and place impossible.