Databases are ubiquitous in modern technology solutions. This is a mature field and well-known best practices are routinely used for deploying databases. Databases provide standard means for accessing and manipulating structured data. Structured means that the data components (fields) are of specific type (integer, string, etc.) and this knowledge helps in querying and manipulating the data.
On the other hand, files stored on the file system are generally unstructured and can contain information in any form. Such files and the unstructured information contained therein are collectively referred to as content.
While databases provide standard means of managing structured data, content management systems (CMS) are a relatively new phenomenon. Since the content itself is unstructured, it is not possible to read and understand the content without any prior knowledge about it. Therefore, some structured data is attached to each content item, which describes the content item. This data that provides information about the attached content item is called metadata.
Content management systems utilize metadata extensively to provide sophisticated functionality. For example, metadata is essential for making documents searchable in terms of their author, title, subject, or keywords. It is hard to imagine any functionality of Documentum that does not utilize metadata in one form or another. The following figure shows two content items and their associated metadata:
