Meta Data is descriptive data that is attached to an object (element) that allows a piece of Content to be more accurately indexed, retrieved, or processed.

It describes the content, and might provide optional information like a caption, abstract, or keywords for search engines. It could include a creation date, publication date, and expiry date.

XML elements are indexed by Meta Data that is described in a DTD or in the XML document itself, enabling other applications to interact with it.

Video data may include camera settings, times and geographical data of the shoot, cameraperson and editor names, etc. It could include copyright information and terms of use. Document Meta Data might include the full list of the Dublin Core ontology properties. It is usually stored in a relational database or an Object Oriented database (the CMS Repository).