XML stands for Extensible Markup Language and is a hierarchically structured document consisting of nested tags that resemble HTML tags.
XML does not mean less storage space or quick access to information. However, XML lets you declare your own tags and is platform independent.
XML also enables the design of domain-specific markup language because namespaces are supported. Here is an example:
<?xml version="1.0" encoding="UTF-8"?>
<Child>Today is monday!</Child>
<Sibling>Tomorrow will be tuesday!</Sibling>
<Another attribute="I wish it were friday!" />