A podcast feed is a way of sharing files over the internet. It involves the use of a small, machine readable file that is regularily updated to reflect changes in the files available for downloading. Podcasting originally occured as a way to share audio mp3 files, and has only recently begun incorporating video into podcasts. However, the technology that allows the files to be shared is not limited to such media files and there is not reason that other files may be shared via podcast in the future.

A Podcast RSS feed is what allows the entire system to function. To begin at the beginning, a podcast is a regular distribution of audio or visual files, called episodes, to a users podcast client. The people who use a podcast are called subscribers, and the podcast client is what allows them to subscribe to a feed.

A podcast client is the software used to access and download podcasts. Podcast clients are also known as media aggregators, programs designed to automatically access an online file, or feed, and download the audio or video file associated with it. Hundreds of these programs exist, with names like IpodderX, Juice, Nimiq, and PodSpider. The podcast client is a program that connects to the internet, looking for a specific file the user has subscribed to, or told it to look for. That file is an RSS feed, a machine readable piece of coding that sends information back to the podcast client. RSS feeds can be used to distribute many kinds of information, and were originally used for blogging and distributing blog posts to subscribers. As time went on, however, a few people had the idea of enclosing information about media files within the RSS feed so that software could be written to find that information and download the files described. A podcast client is the software used to access and download podcasts.

Podcast RSS feeds are now used to distribute a number of different types of podcasts. Some producers use it as way to share a comedy or news program that they produce, others podcast in order to share music files they create, and some podcast to share video files they have created and to showcase their work.

One of the newer innovations in podcast feeds is the vlog, or videoblog. These blogs usually contain a feed that distributes a video, rather than an audio file to feed subscribers. The BBC currently does this with parts of its news content. Pieces of the news show that is played over the airwaves is taken and placed online, along with a link to the content placed inside the RSS feed.

In the future, podcast feeds may be used for a number of purposes besides simply sharing media files. For now, however, podcasting is dominated by small audio and video files.