<!DOCTYPE >
Like <!– … –>, <!DOCTYPE >should be a familiar tag for web programers. <!DOCTYPE > defines the document type. As such it is the first thing that should be included in your web file. In HTML5 there is only one document type, HTML. This is different then in the previous version of HTML.
<!DOCTYPE > tells the browser what type of document and code to expect, allowing it to handle the coding properly. I believe this is the only tag that does not need to be accompanied by a closing tag.
The below example is taken from W3Schools and is a basic layout and framework of a basic webpage:
<!DOCTYPE HTML>
<html>
<head>
<title>Title of the document</title>
</head>
<body>
The content of the document……
</body>
</html>