Check out example codes for "internal css". It will help you in understanding the concepts better.

Code Example 1

<!DOCTYPE html>
<html>
<head>
<style>

 body {background-color: powderblue;}
h1   {color: blue;}
p    {color: red;}

</style>
</head>
<body>

<h1>This is a 
 heading</h1>
<p>This is a paragraph.</p>

</body>
</html>

Code Example 2

<!DOCTYPE html>
<html>
<head>
<style>
body {background-color: powderblue;}
h1   {color: blue;}
p    {color: red;}
</style>
</head>
<body>

<h1>This is a heading</h1>
<p>This is a paragraph.</p>

</body>
</html>

Code Example 3

<!DOCTYPE html>
<html>
<body>

<h1 style="color:blue;text-align:center;">This 
  is a heading</h1>
<p style="color:red;">This is a paragraph.</p>


  </body>
</html>

Code Example 4

<head>
	<link rel='stylesheet' href='style.css'>
</head>

Code Example 5

<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" type="text/css" 
  href="mystyle.css">
</head>
<body>

<h1>This is a heading</h1>

  <p>This is a paragraph.</p>

</body>
</html>

Code Example 6

<link rel="stylesheet" type="text/css" href="style.css">

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