Professors that create courses on edX are able to implement highly interactive experiences that allow you as a student to experiment using easy to use online web applications. These labs are customized to each class and subject area. We have collected a couple of the more popular lab environments here for you to experience and play with.
Please be patient with yourself as you take a look around at these lab environments. You probably will not be able to answer these questions without taking a course on the topic first!