HTML and CSS Reference
The <section> and <article> elements are conceptually similar. Articles
and sections can be interchangeable—articles can exist happily within
sections, but articles can also be broken down into sections, and there's
been a lot of discussion about whether HTML5 really needs both of
them. For now, though, we have both, and you're probably asking
yourself how to decide which one to use. The key parts of the spec to
focus on when choosing one or the other are as follows:
An article is intended to be independently distributable or reusable.
A section is a thematic grouping of content.