ABSTRACT
The range of metadata activity over this last decade is both extensive and astonishing, and substantiates metadata as an integral part of our digital information infrastructure. This entry begins with a brief history of metadata relating to digital information, followed by an overview of different metadata types, functions, and domain-specific definitions. Next, the family of standards comprising a metadata architecture are defined, followed by an overview of metadata generation processes, applications, and people: this latter section gives particular attention to automatic metadata generation approaches. The following section explores four key metadata models. The conclusion summarizes the entry, highlights a number of significant metadata challenges, and notes efforts underway to address metadata challenges in the new millennium.
