Zettelkasten is a knowledge management method originally used by Niklas Luhmann. It also refers to a system which follows this method.

The most important properties of zettelkasten are:

  1. Notes are linked. Each (forward) link should explain why to follow the link in the context, since the zettelkasten will be ‘surfed’ by future self. These links are like hyperlinks
  2. Notes should be atomic. It only contains one unit of knowledge: principle of atomicity. This is because we link to knowledge, not information.
  3. zettelkasten is personal. It is formed by the unique mind of a person.