What we know as a podcast had its beginnings in the creation of MP3 files that could be downloaded and played on the iPod device developed by Apple Computer. The release of the iPod encouraged people to share their music with others. They then realized that they could create, upload, and download information other than music. Some iPod users reverse engineered the device and loaded various types of firmware or operating system software. Other users decided that they would share sound files to be played on the iPod, since the technology for distributing such files already existed. RSS feeds provide a way to generate machine-readable files, which could then share data between servers and users. Many blogs used RSS to keep their readers up to date on blog posts. Some visionary podcasters realized that they could enclose links to sound files inside the RSS feed and download these files to a computer.

The iPod podcast became increasingly popular as this change in RSS feeds was implemented. Podcasting became a common way to share files, and users began to view podcasting as a way to become, essentially, radio-show hosts or DJs. Then software was developed that would automatically check the RSS feeds, extract links to podcast episodes, and download the files. This software is called a podcast client.

By the time all this was happening, podcasting had expanded far beyond Apple's iPod device. Developers had even discovered ways to use PlayStation Portable gaming systems as a podcast player. While this was more difficult than downloading a podcast to an iPod because of PSP's different file format, more PSP podcasts began appearing on the Internet. Podcasting also expanded into use by individuals who didn't have iPods, but who viewed podcasting as a very convenient technology for receiving news, music, and entertainment over the Internet.

Now, iPod podcasting remains in use, but fewer people subscribe to podcasts in order to get portable media files. This still represents an attractive feature of podcasting, but it is overshadowed by the use of podcasting as a content delivery system. Podcasting is currently associated with a large and growing number of audio and video blogs, for example. With these offerings, content is not delivered via posting, but through media files that are uploaded to the blog. These types of blogs, and podcasting in general, benefit from the constantly decreasing cost of broadband Internet connections and the growing number of people who have high-speed access to rich online content that includes multimedia files.