The Leitner system (a.k.a Leitner Boxes) is a powerful learning system for memorising information using flashcards. It was created by the German science journalist Sebastian Leitner.

It basically consists of dividing your deck of cards in boxes and studying each box separately depending on how often you recall them.

It's really simple!

The example below assumes that you are using 3 boxes, but the idea is the same with more boxes.

1️⃣ You start with Box 1

2️⃣ Next up is Box 2

3️⃣ Last up is Box 3

A (moving) picture is worth a thousand words

References you should check