Terminology

• Document Type Definition (DTD)
  • to ensure that all dataset descriptions are of a consistent type
  • the DTD defines the metadata elements, and their order, structure, and relationships
  • set of rules
  • allows different instances of documents of the same type to be automatically processed in a uniform way
  • referred to by XML documents of this type
• Document instance
  • an actual XML document

  • contains

    - all of the text content,

    - the markup that conforms to the DTD,

    - and a declaration of which DTD to use

• Markup
  • instructions or codes embedded in text to indicate how the text should be processed
  • specifies what the text respresents, rather than what it should look like
  • the markup must conform to the DTD rules
  • <title>XML DTDs rule, OK!</title>
• Parser
  • a computer program that reads a document and distinguishes all of the separate elements
  • determine the relationships between elements of the document
  • ensure that the document structure complies with the rules of the DTD

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