If you are completely unfamiliar with the notion of a Podcast, consider them akin to talk radio on Tivo. Podcasts are audio files published on a (usually) regular or predictable schedule. Listeners or Subscribers then tell computer clients (sometimes called Pod Catchers), of which iTunes is one of the more popular, to check for recently-published audio files (often called Episodes). You, the Podcaster, get to be like the talk-show host, the internet is like the radio waves, and the subscriber is like the person caught in rush-hour traffic with nothing better to do. The key difference, however, is that the Subscriber can keep the Episodes as long as he or she wishes and listen to them at his or her leisure.

The way the above paragraph describes Podcasts is silightly simplified, of course. We can tell that just by looking at this workshop's title--it includes "Vodcasting." We put that there to emphasize an important aspect: podcasts are not strictly audio. Podcasts can contain any one of hundreds of different media files including MP3s, PDFs, MOVs, AVIs, and all such manner of content. It really gets interesting when content types are mixed. Include with your video file a copy of its audio and a PDF for its notes. Lectures can now be Podcasted as often as they are presented complete with overhead notes or even the PowerPoint files to go with them. Podcasting has many more implications than just recorded talk radio.

Podcasts are a form of RSS feeds and are generally audio or video files. Podcasts are shared on the Internet for anyone to download or subscribe to. Earlier we said that the internet is much like the radio waves of talk radio. RSS, then, is similar to the radio tower. RSS is used as a sort of way to give Subscribers information about Podcasts and tell them when new episodes are available. Podcatchers use the internet to periodically connect to the RSS feed and check for new episodes. If the Podcatcher sees that there is a new episode available in the RSS feed, it will download it.

What is RSS then? To explain that without first explaining XML would be like trying to explain addition without first explaining numbers. RSS uses a technology called XML. In fact, RSS is just a specialized (and much more strict and less forgiving unfortunately) form of XML. The next page gives some of the ground work for XML.

In case you missed some of that terminology, here is an abridged glossary of terms we just covered.

Podcast

A series of files grouped together by a Podcaster and distributed over the internet via an RSS feed which can be subscribed to by Subscribers using a Pod Catcher

Pod Catcher

Any software that regularly checks an RSS feed for updates to a Podcast. Pod Catchers may or may not be able to put these files onto an iPod or other portable media device. Common Pod Catchers include Apple's iTunes and an open-source program called Juice. We will cover both of these later in the curriculum.

Episodes

Any files within a Podcast's RSS feed. We call them "Episodes" because they are commonly audio or video files, but any file in a Podcast could be considered an episode. Many Podcasts are limited solely to PDF documents. Each of these documents would be considered an episode. Similarly, if both audio and text were distributed on the same Podcast, each one would be considered its own episode even if they were direcly related to each other as much as notes are related to their concrete material. Such a distinction will become more clear once we cover creating RSS feeds

Podcaster

You! Anybody publishing a Podcast is called a Podcaster. Many Podcasts are published by a group of Podcasters or even corporations dedicated to their production.

RSS

An acronym for Really Simple Syndication. It sits on top of XML. An RSS "feed" is simply an XML file that is highly specialized to give information that a program is expecting to know. A Pod Catcher, in particular, is looking for certain information in the RSS feed about the Podcast, what episodes are available, when they were published, etc. RSS provides us a very concrete and predictable way to give this information to the various Pod Catchers so they can all see and use it in the same way.

XML

An acronym for eXtensible Markup Language. It is formatted very similarly to HTML--by which it was inspired and conceived. XML is simply a heirarchical way of delineating, storing, and delivering information. It is now very widely used and supported in lieu of the many hundreds of proprietary formats that used to plague information systems to the point of inoperability. We will cover the basics of XML in this workshop.