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 was designed to describe data and to focus on what data is.
- HTML was designed to display data and to focus on how data looks.
- HTML is about displaying information, while XML is about describing information.
XML Does Not Do Anything.
XML was not designed to do anything. Maybe it is a little hard to understand, but XML does not do anything. XML is created to structure, store, and to send information. The following example 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