HTML <main> Tag

<!DOCTYPE html>
<html>
<head>
<style type="text/css">
header, article, aside, footer, main, nav {border:8px solid #F9EECF;padding:3px;margin:3px;width:50%;} 
</style>
</head>
<body>
<header>Header...</header>
<main>
Main...
<article>Article...
<aside>Aside...</aside>
</article>
</main>
<footer>Footer...
<nav>Nav...</nav>
</footer>
</body>
</html>

The above example demonstrates usage of the <main> element.

The <main> element represents the main content of the <body> of the HTML document or application. This consists of content that is directly related to or expands upon the central topic of a document or central functionality of an application.

The <main> element should not be used to provide site navigation links, copyright information, site logos, banners, site-search forms (unless the document's main function is to provide search).

There must not be more than one <main> element in an HTML document.

Also, the <main> element must not be a descendent of any <article>, <aside>, <footer>, <header>, or <nav> elements.