A module is a tab that can be found in all of your courses. This tab holds your assignments, assessments, discussions, etc.
You can find this when you click on the course selection. On the left-hand side of your screen, there would be several options, and one of them says Modules. Click on that, and you will be shown all the assigned content from your teacher. You can see that a “module” is an organized folder consisting of all assigned content.