The 4 Main Document Elements
Everything is HTML is described through elements. This includes the larger structure of the main document.
  In this sub-topic, we'll build the basic structure of a single page, going step-by-step through the standard page elements. It is worthwhile to note that, usually, there is only one set of each of these elements per page, beginning with a <!DOCTYPE> declaration. We can even compare these elements to your own very structure.
Important The 4 elements every HTML page you'll make will need to have:
- The 
<!DOCTYPE>declaration. - The 
<root>element. - The 
<head>element. - The 
<body>element. 
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