A waitlist is just that - a list of people waiting to get into a class. If a class is full, you will be able to get on the waitlist by selecting the "waitlist" option when trying to add. If someone drops and you are the first person on the waitlist, you will automatically get registered for that class, you will receive a message in MySJSU notifying you that you have been let into the course, and everyone else on the waitlist will move up a spot. There is no way to estimate how long you might be on a waitlist or even if you will move up on it. Waitlists are a gamble; they are active until the end of Advance Registration but if you sit too long on a waitlist you may not get another section of the class. It’s better to enroll in another class section that is still open than to sit on a waitlist too long.