Podcasting has its roots in audio blogging from the 1980s but wasn't termed "podcasting" until 2004 when the necessary technology became available. Podcasts are digital media files, usually featuring discussions on certain topics, that are released periodically and can be downloaded for free from the internet. Creating a podcast involves deciding a topic, recording audio in mp3 format, and uploading the file to hosting services like iTunes or YouTube to be distributed. Podcasts are a popular medium that can be educational, entertaining, or informative for both listeners and those wanting to establish expertise in a field.