Hello Chuck, Modules are fully realized adventures that a GM can pick up and play that does most if not all of the setup work for them. You can find more information about modules here on our wiki page. A note about Tales of the Yawning Portal. In this case, purchasing the Tales of the Yawning Portal is purchasing a bundle of addons . These are like smaller modules. You will need to add an addon via the Game's setting page under addons. Modules are selected when initially setting up the game. If you have any additional questions, feel free to let us know. Happy playing.