Zettelkasten

Building on the word zettel, a zettelkasten is a box that holds zettels. The plural for zettelkasten is zettelkästen

Wait but there’s more than that. Developed (or perhaps popularised) by the German sociology researcher Niklas Luhmann, the zettelkasten system is also a note taking system that serves as a robust personal knowledge management system.

Though different from Niklas Luhmann’s physical zettelkasten, this notebook employs some of its underlying principles as discussed in Note-Taking System.