Each class session is scheduled within a 1 to 3-hour block. In a week you should expect to have 2-4 classes, 4-8 hours of class time total, it is depending on the chosen course. Lessons might be recorded, in this case, you can download the videos at any moment of the day, and live, which are scheduled with the instructor. A class will typically consist of a theoretical or practical lecture, a homework review, a short Q&A session, intermediate and final exams, and a work project if it is requested.