Comments are ignored by web browsers. Comments are used to explain the code, and comments may help you edit code at a later time. Comments do not affect the code.
Single line comment is used to hide a single line of the source code.
<style>
	/*comment*/
	/*h1{color:red}*/
	p{background-color:green;/*height:500px*/}
</style>We can use Multiple lines comment to hide multiple lines of source code.
<style>
	/*multi-line comment*/
	/*h1{color:red}
	p{background-color:green;height:500px}*/
</style><!DOCTYPE html>
<html>
	<head>
		<style>
		/*single line comment*/
		/*h1{color:red}*/
		/*multiple lines comments*/
		/*p{background-color:green;height:500px}
		h1{color:pink}*/
		h1{color:green}
		</style>
	</head>
<body>
<h1>Hello world!</h1>
</body>
</html>