XML
XML (Extensible Markup Language) is a language used to store textual information in a document format.
XML is written using custom defined tags and looks a bit like HTML. Where HTML consists of predefined tags, in XML you can define your own tags for greater flexibility. An example of XML is:
<?xml version="1.0"?>
<book id="583">
<title>Learning XML</title>
<author>Erik T. Ray</author>
<published>
<by>O'Reilly Media</by>
<year>2001</year>
</published>
</book>
An XML file can also be used to transport data over the internet. However, JSON can be parsed by JavaScript, where XML needs to be read by an XML parser.