It’s up to you. Make it work according to how you prefer to organize your notes. I dont follow the Zettelkasten system. I create notes per category or tag under which i can look for backlinks into related material. But otherwise I just use is to store everything, including lecture notes, vocabulary and full text of articles or lectures I consider important.
There’s a graph server that might be helpful but I never used it.
Another advantage being able to ripgrep through content for dirty searches.
The more content is there (not just links and pointers) the more likely it is you’ll surprise yourself finding links between different domains you’re interested in.
For me, word definitions in Arabic for example, tie into terminology used in articles I read in other languages, because I can use “aliases” to refer back to them.