What is an ontology? At least in context of web development

Any references to text books would also be appreciated开发者_如何学JAVA.

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Check out this SE-RAdio episode on Semantic Web which will explain much for a start I guess.

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See wikipedia: http://en.wikipedia.org/wiki/Ontology_(information_science).

In context of web development: visualising tag clouds, the (still not really here) semantic web...