Memorang Power-Ups are professionally authored and take up to a thousand hours to produce. As part of this process they are fact-checked and updated regularly so you always have the most up-to-date and accurate information to learn for your exams. Free flashcard decks available online are authored by anonymous students and contain personal notes. While both are digitally available, the main differences come down to trustworthiness, comprehensiveness, quality, and accuracy. Studying freely shared, anonymously authored flashcards involves a risk/benefit tradeoff that only you can make depending on your learning goals.