Spaced Repetition is our most scientifically advanced study mode, based on the "forgetting curve" theory of cognitive science. Rather than "cramming" all at once, this mode schedules your reviews at strategically timed intervals—hours, days, or weeks apart—depending on how easily you recall each card. Cards you find difficult appear more frequently, while cards you know well are shown less often. This method maximizes brain retention and ensures that you remember the information for months or years, rather than just until your next test.