HTML is powerful but does not separate display and form
(structure of document component as an
object)
XML is a generalization of HTML which allows definition of
arbitrary tags
e.g. <student
name=Jane Doe class=CSIT:IT1 grade=
>Working Hard</student> is more elegant way of capturing information in a reliable fashion than HTML
<h2>Students</h2>
<ul><li>Jane Doe: Working
Hard</li><ul>
<li>Class:
IT1</li>
<li>Grade:
</li>
.
</ul>
</ul> with a PERL
program to extract data
XML allows powerful way of defining dynamic ascii databases useful for modest
size data such as people, document citations etc.
XML
parsers map XML tags into HTML for display
or hand to programs to interpret
XML can also be used to define extensions to HTML such as special tags
for mathematics (MathML) or chemistry or
..
XML defines syntax for serializing Web objects and
transmitting between clients and
servers SOAP