People put all kinds of stuff in Notion. People use it as a DB. People catalog things they find online (web clipper). There's collaboration features.

There are many ways

If I had to describe it, Notion is if somehow managed to combine OneNote and Excel. Of interest is the fact that the "database" system stores each row as a page with the column values other than title stored in a special way. Of course, this also means that it doesn't scale at all, but I have seen some crazy use cases (an example is replacing Jira).