20.5. Schema and schema definition The programming and database worlds have introduced some new terminology to XML. We now speak of a document type as a kind of schema, a conception of the common characteristics of some class of things. Similarly, a DTD is a schema definition, the rules for using XML to represent documents conforming to the schema. Schema definitions are invariably written out in a notation called a schema definition language, or simply a schema language. And as with DTDs, the word "schema" can serve for all these purposes when there is no ambiguity. |