Metadata

Data about data. Metadata describes how, when, and whom a particular set of data was collected, and how the data is formatted. Metadata is essential for understanding information stored in data warehouses and has become increasingly important in XML based web applications – web 2.0.

//Administrative// - for purposes of managing the resource: security, created, application //Descriptive// - facilitates discovery and identification: keywords, abstract, author //Structural// – indicates how objects are combined: page order for chapters
 * Types of Metadata**:

Wikipedia article on [|Metadata]

media type="youtube" key="sdLg-tWum9E" width="425" height="350" Video on the use of metadata in Photoshop