All about spaced repetition
Spaced repetition is a technique for studying material where the material is reviewed on a schedule that is gradually spaced out over time, based on how well you remember the material. Material that is difficult to remember is reviewed more frequently, and material that is easily remembered is scheduled further into the future to review again.
Modern spaced repetition software is heavily influenced by SuperMemo, which pioneered the spaced repetition algorithm. Many apps, such as Anki, make use a variant of SuperMemo’s original SM-2 algorithm.