what is html

HTML
HYPER-TEXT MARKUP LANGUAGE
Is the standardised markup language (a subset of XML) that 
defines the layout of a webpage. 
HTML has no functional properties, other languages such as 
JavaScript must be used in order to manipulate the layout
and perform HTTP requests.
CSS (Cascading Style Sheets) is commonly used to style the
elements in the layout. p
<p>
hello world
</p><!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>HTML basics</title>
    </head>
    <body>


    </body>
</html><!DOCTYPE html>
<html lang="pt-br" xml:lang="fr" xmlns="http://www.w3.org/1999/xhtml">
<head>
	<link rel="stylesheet" type="text/css" href="style.css">
	<title>...</title>
</head>
<body>
	...
<script type="text/javascript" src="script.js"></script>
</body>
</html><!DOCTYPE html>
<html><head><title>Page Title</title>
</head><body><h1>This is a Heading</h1><p>This is a paragraph.</p>
</body></html>
 
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Also in HTML: