I don't describe them as classes because they'Bezeichnung für eine antwort im email-verkehr not formal, organized sessions which form part of a course, hinein the way that the ones I had at university were. 知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。 Actually, they keep using these two words just like this all the time. https://youtu.be/T0zWXvhEQwo?si=wNc6ihu97ShtIl7u