Extensible Markup Language

eXtensible Markup Language (XML) is a W3C markup language derived from SGML (ISO8879) used in a wide variety of applications for the storage and representation of textual data.

Usage Examples

Data Storage

Address Book Example

Suppose Thomas wants to write a simple address book program that stores his addresses and phone numbers in a simple structured manner. He decides his best option is to use XML to store his information because he can define what information he wishes to store. XML works best when the information has a hierarchical arrangement, so Thomas designs the schema of how his information will be held.

• Person or Company Name
  • Addresses
    • Mailing Address
    • E-mail Address
  • Phone Numbers
    • Fax Number
    • Cell/Mobile Number
  • Note

This arrangement of data is then transformed into XML, one possible arrangement is below:

<?xml version="1.0">
<person name="Thomas Paine">
    <addresses>
        <mailing>812 Juniper Road</mailing>
        <email>tpaine@foo.net</email>
    <telephone>
        <primary>987-654-4321</primary>
        <fax>555-555-5555</fax>
        <cell>123-456-7890</cell>
    <note>Me.</note>
</person>

See Also

• SGML
• HTML
• SVG