Zettelkasten and Evergreen MOC
This is (mostly) a stub
Literature notes
Fleeting notes
Categories are buckets, everything gets just dumped into them. Keywords, with the key-part of the word key, are specific, used to locate an idea. It is as a thumbnail for a note, even shorter and more general then a title, thus making the application even wider. This will help connecting even more dissimilar ideas.