Metadata

Metadata is "data about data".

Description

Two types of metadata are commonly distinguished:

• Structural metadata, about the design and specification of data structures or "data about the containers of data"

• Descriptive metadata about individual instances of application data or the data content

Markup languages

A markup language, for example HTML, uses tags in an HTML document to annotate the document.

HTML tags are metadata about the content and format of the text, not part of the text itself.

History

Metadata was traditionally in the card catalogs of libraries.

As information has become increasingly digital, metadata are also used to describe digital data using metadata standards specific to a particular discipline.

See also

• Data
• Data analysis
• Data mining
• Web indexing

External links

• Metadata @ Wikipedia