XML is a markup language and subset of SGML, created to provide functionality that goes beyond that of HTML for Web publishing and distributed document processing.
XML is less complex than SGML, but more complex and flexible than HTML. Although XML and HTML can usually be read by the same browsers and processors, XML has characteristics that make it better able to share documents:
XML documents possess a strict phrase
structure that makes data easy to find and access. For example,
opening tags of all elements must have a corresponding closing tag,
as in the element <p>A paragraph.<\p>.
XML lets you develop and use tags that distinguish different types of data, for example, customer numbers or item numbers.
XML lets you create an application-specific document type, which makes it possible to distinguish one kind of document from another.
XML documents allow different views of the XML data. XML documents contain only markup and content; they do not contain formatting instructions. Formatting instructions are normally provided on the client using Extensible Style Language (XSL) specifications.
