tailieunhanh - XML Step by Step- P2

XML Step by Step- P2:Extensible Markup Language, or XML, is currently the most promising language for storing and exchanging information on the World Wide Web. Although Hypertext Markup Language (HTML) is presently the most common language used to create Web pages, HTML has a limited capacity for storing information. In contrast, because XML allows you to create your own elements, attributes, and document structure, you can use it to describe virtually any kind of information from a simple recipe to a complex database | PART 1 Getting Started CHAPTER 1 Why XML Why XML XML which stands for Extensible Markup Language was defined by the XML Working Group of the World Wide Web Consortium W3C . This group described the language as follows The Extensible Markup Language XML is a subset of goal is to enable generic SGML to be served received and processed on the Web in the way that is now possible with HTML. XML has been designed for ease of implementation and for interoperability with both SGML and HTML. This is a quotation from version of the official XML specification. You can read the entire document at http TR REC-xml on the W3C Web site. note As this book goes to press the current version of the XML specification is still . The first edition of this specification was published in February 1998. The second edition which merely incorporates error corrections and clarifications and does not represent a new XML version was published in October 2000. You ll find the text of the second edition at the URL given above http TR REC-xml . The XML specification has the W3C status of Recommendation. Although this status might sound a bit tentative it actually refers to the final approved specification. The role of the W3C is to recommend standards not to enforce them. As you can see XML is a markup language designed specifically for delivering information over the World Wide Web just like HTML Hypertext Markup Language which has been the standard language used to create Web pages since the inception of the Web. Since we already have HTML which continues to evolve to meet additional needs you might wonder why we require a completely new language for the Web. What is new and different about XML .