I've seen an ongoing debate between "Note" versus "Article" in ActivityPub / ActivityStreams.
When is something a "Note"‽
When is something an "Article"‽
Personally — I would probably have made the distinction this way.
An "Article" has a title.
A "Note" doesn't have a title.
(In ActivityPub / ActivityStreams, a 'title' seems to tend to get represented in the "name" field.)