Here are just some of the article types in PubMed:
There is a great amount of information availabe in different formats online. Just because it is online does not mean it is a journal article, and different articles have different purposes.
Here are just some of the article types in PubMed:
When you are in a detailed record in PubMed look under Publication Types to determine the type of article it is:
To the untrained eye this may look like a research article, but this is only a two page editorial.
When you are in a detailed record in CINAHL look for publication type to determine the type of article: