You can use this quizlet app to help you learn the important terms for each concept and theory. The default mode for quizlet is similar to flashcards. You can click the term to flip the card and see the definition. You can click the arrows at the bottom to move between terms. The options gear in the upper-right corner allows you to change the settings. The drop-down menu in the lower-right corner allows you to study the words in many different ways, including some game-like modes.