XML Guid
XML-Extensible markup language
XML is a cross-platform tool for transmitting information that is independent of software and hardware.
XML document instance
<?xml version="1.0"?>
<note>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don't forget me this weekend!</body>
</note>
What is XML?
XML refers to Extensible markup language (EXtensible Markup Language)
XML is a markup language, very similar to HTML
XML is designed to describe data
The XML tag is not predefined. You need to define your own label.
XML uses a file type declaration (DTD) or XML Schema to describe the data.
XML with DTD or XML Schema is designed to be self-descriptive.
XML is a W3C standard
XML won’t do anything.
ML is not doing anything. XML creates structures, stores and carries information.
The example of the XML document above is a note written by XML from Jani to Tove. Pay attention to the title and the body of the email. It also has information about where it comes from. However, this XML document doesn’t doanything. It’s just pure information wrapped in XML tags. Someone must write a piece of software to send, receive or display it:
MESSAGE
To: Tove
From: Jani
Don't forget me this weekend!
XML tag is not predefined
XML tags are not predefined, you must “invent” your own tags.
The tags used to mark HTML documents are predefined. HTML file authors can only use tags defined in HTML standards (such as <P>, <H1>, etc.).
XML allows the author to define his / her own tags and his / her own document structure.
The tags in the above examples (such as < to > and < from >) are not definedin any XML standard. These tags were “invented” by the author of the XML document.