XML is a cross-platform, software and hardware independent tool for storing and transmitting information.
XML was not designed to DO anything. XML was created to structure, store and carry information.
The XML document example above is a note, to Tove from Jani, written in XML. The note has a heading and a message body. It also has to and from 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:
Don't forget me this weekend!
XML tags are not predefined. You must "invent" your own tags.
The tags used to mark up HTML documents are predefined, the author of HTML documents can only use tags that are defined in the HTML standard (like <p>, <h1>, etc.).
XML allows the author to define his/her own tags and his/her own document structure.
The tags in the example above (like <to> and <from>) are not defined in any XML standard. These tags are "invented" by the author of the XML document.
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