Article: for informative short or large chunks of text related to or about/referencing something in or outside of current site. "section" or "aside" can be used in separate instances not defined as similar to in usage as mentioned above for the "article". So an example would be, needing to reference a book and including author for crediting purposes only, and description about author and outside of this, the book and or author is unrelated to content held on site and used for ref only, would be good for this scenario. If it's more relative to content of site or "section" would be good