Tag is a type of meta-information that describes or defines some aspect of a data resource (such as a document, digital image, relational table, or web page). Tags are more than traditional non-hierarchical keywords or terms. They are a type of metadata that captures knowledge in the form of descriptions, categorizations, classifications, semantics, comments, notes, annotations, hyperdata, hyperlinks, or references that are collected in tag profiles. These tag profiles leverage Enterprise 2.0 methodologies for users to capture insights, expertise, attributes, dependencies, or relationships associated with a data resource. It generally allows greater flexibility than other knowledge management classification systems.