Zettelkasten and Evergreen notes
Concepts, or abstracts ideas are more wikipedia then zettelkasten. But, when studying a subject, especially in the beginning, having those kind of notes in your PKM can be helpful. Make sure to not just import definitions from wikipedia (with the obsidian wikipedia plugin), but rewrite the idea in a way that is clear to you translating is better than copying / transcribing.
For further understanding, link your concept-notes to other notes. Try to look at the idea from different directions: why is it useful, how could it be applied, etc
Concepts make bad (ZK) notes, they are too general, and do not make specific ideas clearer. They are good as buckets, ways to group ideas together. Concepts are wikipedia, not zettelkasten
Still, you often need concepts as a zettel’s (=atomic note) context for understanding related ideas
(Primary) Sources
A Noun Note is an evergreen note who’s title is simply the name of the concept. This is in contrast to a notes with Assertive Note Titles and Assertive Notes source
Concepts are defined as abstract ideas. They are understood to be the fundamental building blocks of the concept behind principles, thoughts and beliefs. They play an important role in all aspects of cognition. As such, concepts are studied by several disciplines, such as linguistics, psychology, and philosophy, and these disciplines are interested in the logical and psychological structure of concepts, and how they are put together to form thoughts and sentences. The study of concepts has served as an important flagship of an emerging interdisciplinary approach called cognitive science. — Wikipedia
Restating facts is a form of paraphrasing, And, in that there is some value. Paraphrasing can help writers distill complex ideas into terminology that’s specific to themselves, converting the information into something more personal. consider creating new notes so you can speak about the fact itself. By providing additional commentary, you can better integrate the information into your broader understanding of the topic, Comments about how a fact shows up in your daily life, how a fact is regarded in public discourse, how a fact is disputed, all make for valuable content. – How to Handle Facts in Your Zettelkasten - Writing by Bob Doto Bob Doto