There are many different types of metadata, some of which may have a formal structure and content, and some informal with no structure or consistency. From the file size or date of modification displayed by Windows, through the information about a book held in a library catalogue, to the statement of copyright (©) denoting ownership, people are accustomed to the idea of information about an object being associated with it.
In the context of a digital asset management strategy, metadata contains the fundamental information components of asset retrieval and management. It is the record about the asset and its contents.
"Metadata: Data about other data, commonly divided into descriptive metadata such as bibliographic information, structural metadata about formats and structures, and administrative metadata, which is used to manage information." From the 1999 manuscript of Digital Libraries, by William Arms, ©2000 M.I.T. Press.
There are a variety of types of metadata:
- Bibliographic (e.g. "a picture of the Eiffel tower taken by Bob")
- Administrative (e.g. "taken on 19/04/2005")
- Legal (e.g. "all rights reserved")
- Preservational (e.g. "requirement to view as jpeg")
- Technical (e.g. "jpeg format" ; "85.8kb file")
- Educational (e.g. "an illustration of construction using cast iron"; "UK Education Level 11")
- Structural (e.g. "single file")