Below is a diagram which illustrates the various components involved in delivering and receiving a podcast
Each component is described in more detail below:
Content - A podcast will involve a number of digital files hosted on the Internet. Each podcast episode is represented by one of these files. In general these are files encoded in a standard format such as MP3 so that they can be played on the majority of digital media players and PCs.
Podcast Feed - This is a simple file which basically consists of a list of the podcast episodes with some additional descriptive information called metadata. This metadata provides details of the podcast and also details for each episode which helps a listener decide whether to subscribe to the podcast and then which episodes to listen to. This file also includes the details of where the media file for each episode is located on the Internet (given as a web address e.g. http://www.567.co.za/episode1.mp3) so the podcast aggregator knows where to find it.
Feeds are generally automatically generated and written in code called XML conforming to a standard such as RSS (Really Simple Syndication).
Podcast aggregator - This is PC based software that provides specific functionality for subscribing to and receiving existing podcasts. Typical functionality of this software includes:
Subscribing to a podcast feed.
Regularly checking subscribed podcast feeds for updates.
Alerting the listener when a new podcast episode becomes available.
Downloading the episode file from the Internet.
Playing the audio file.
Transfering the audio file onto a portable media player (e.g. synchronising with an iPod).
There are many software packages that provide this functionality most of which are free e.g. iTunes & Juice.
Note - there are also web-based podcast aggregators which provide similar functionality via a secure website. These systems do not download and transfer the podcast episodes on to a portable playing device and therefore require podcast episodes to be listened to on a PC that is on the Internet.
Portable digital media player - a small electronic device that stores and plays audio files. The most well known example is the iPod but there are many others. In addition many modern mobile phones can receive and play podcasts with free software such as that offered by Pod2Mob.