A flashcard or flash card is a card bearing information on both sides, usually intended to practice and/or aid memorization. It can be virtual (part of a flashcard software) or physical.
Typically, each flashcard bears a question or definition on one side and an answer or target term on the other. As such, flashcards are often used to memorize vocabulary, historical dates, formulae, or any subject matter that can be learned via a question-and-answer format.
Flashcards are an application of the testing effect, the finding that long-term memory is increased when some part of an individual's learning period is devoted to retrieving information through testing with proper feedback. Study habits affect the rate at which a flashcard user learns, and proper spacing of flashcards has been proven to accelerate learning.[1]