Check out example codes for "structure of an html document". It will help you in understanding the concepts better.

Code Example 1

<!DOCTYPE html>
<head>
	<!-- Miscellaneous Stuff Here -->
</head>
<body>
	<!-- Main Divs here -->
</body>

Code Example 2

<!DOCTYPE html>
'Inserts the DTDs'

Code Example 3

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>A website</title>
  </head>
  <body>
  	...
  </body>
</html>

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