XML (eXtensible Markup Language)
What Is XML?
- XML stands for eXtensible Markup Language.
- XML is a markup language much like HTML.
- XML was designed to describe data.
- XML tags are not predefined. You must define your own tags.
- XML uses a Document Type Definition (DTD) to describe the data.
- XML with a DTD is designed to be self-descriptive.
The Main Differences between XML and HTML
- XML was designed to carry data.
- XML is not a replacement for HTML.
- XML and HTML were designed with different goals:
- XML is to describe data and to focus on what data is.
- HTML is to display data and to focus on how data looks.
- HTML displays information, while XML describes information.
XML Does Not Do Anything.
XML was not designed to do anything.
It may be hard to understand, but XML does not do anything.
XML is created to structure, store, and to send information.
The example below is a note to Tove from Jani, stored as XML:
<note>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don't forget me this weekend!</body>
</note>
The note has a header and a message body.
It also has sender and receiver information.
But still, this XML document does not do anything.
It is just pure information wrapped in XML tags.
Someone must write a piece of software to send, receive, or display it.
An Example of Non-XML Data