Podcast : Audio , video Optimization

A podcast is a series of digital media files (audio or video) that are released in episods and often downloaded through web syndication.
A podcast is a digital audio or video file that is episodic, downloadable, programme-driven, mainly with a host and/or theme, and convenient, usually via an automated feed with computer software. To avoid a term suggestive of "iPod", some use the term netcast instead of podcast.
Metadata and podcasts
In the past, many multimedia search engines relied heavily on metadata to determine relevancy. Now these search engines are able to utilize speech recognition to determine the content of an audio file.