The article tag
The article tag is intended for independent, self-sufficient website blocks that can be used as a standalone page.
For example, if you have a site with articles, then the article can be placed in this tag. If you have user comments, then each of these comments can be placed in this tag.
That being said, if you have a main tag for site content, then article can be placed inside main, but not vice versa.
Example
Let's format the article text in the tag article:
<div id="wrapper">
<header>
...
</header>
<main>
<article>
<h1>Header</h1>
<p>
text
</p>
<p>
text
</p>
</article>
</main>
<footer>
...
</footer>
</div>
Example
Let's format posts in the tags article:
<div id="wrapper">
<header>
...
</header>
<main>
<h1>New posts</h1>
<article>
<h2>Post 1</h2>
<p>
text
</p>
<p>
text
</p>
</article>
<article>
<h2>Post 2</h2>
<p>
text
</p>
<p>
text
</p>
</article>
</main>
<footer>
...
</footer>
</div>
