Anki is a powerful flashcard-based learning tool that uses spaced repetition to help users memorize and retain information more effectively. It allows users to create custom flashcards with text, images, and audio, and then reviews them at optimized intervals to enhance long-term memory retention. Anki's flexibility makes it suitable for a wide range of subjects, from language learning to medical studies, and it supports syncing across multiple devices, enabling seamless studying on-the-go. Additionally, Anki offers access to a vast library of shared decks created by other users, covering numerous topics.