What is the difference between the article and section elements in HTML?

• article is intended for standalone, independent content that can exist outside the context of the rest of the page. Example: a blog post, an article, a comment.
• section groups related content within a document. It does not necessarily have to be independent. Example: a chapter section, a news block on the homepage. Each section usually has a heading.

Key difference: article is a self-contained block that can be syndicated or distributed separately; section is a thematic grouping of content within a document.