XML introduction

 

Extensible Markup Language (XML) allows you to describe and organize information in ways that are easily understandable by both humans and computers. You can then share that information and its description with others over the Internet, an extranet, network, or in other ways.

XML, like Standard Generalized Markup Language (SGML), is a metalanguage. A metalanguage allows you to define a document markup language and its structure. For example, both XML and Hypertext Markup Language (HTML) are derived from SGML.

You can use XML to create your own markup language that includes a set of rules and tags that describe information suited to your needs, for example, name, title, address, and zip code. You define this markup language in a document type definition (DTD) or XML Schema file that functions as the standard way to describe your information. Using XML to share standardized information means you are no longer required to write programs to focus on proprietary software or convert and translate different data formats.

You and others can use the DTD or XML Schema definition to tag information that you can then use in a variety of ways: printed on an address label, business card, or stationary; displayed in a Web page; or sorted in a list of data with similar attributes. For example, you might want to create an efficient way to share information (such as purchase orders, shipping acknowledgments, order status, and stock status) with your partners and suppliers. You can use XML to share that information by creating and using XML documents that conform to your DTD or XML Schema, in which you specify the standard for the electronic exchange of information.

Although both XML and HTML use tags to describe content, they are also very different:

• HTML describes how to format information for display and is meant for computer-to-human interaction.

• XML describes what the information is and is meant for computer-to-computer interaction.

There are many other sources of information regarding the advantages and uses of XML that are readily available on the Internet and through commercial publications. For a complete and comprehensive understanding of the capabilities of XML, you should consult these sources.

• Advantages of XML
  Using XML to exchange information offers many benefits.

• Uses of XML
  XML has a variety of uses for Web, e-business, and portable applications.

• XML standards and extensions
  Other standards and extensions to XML work together to make your information more portable and useful.

 

Parent topic:

XML Toolkit for IBM System i5