This is a lecture that really explains the concepts very well. It seems that you know and understand the program so well that I am amazed and envious, and I really want to learn all of it! The only complaint is that when you demonstrate something... the approach suddenly changes during the lecture, or the editing jumps around, so my results that I followed until the middle are different from the appearance demonstrated after the suddenly changed editing point, and there are parts that seem to be missing, which is disappointing. Up until the beginning, it was okay to review or grasp the concept even if the same content was repeated twice, but Section 7 and Section 9 are a bit confusing because the editing suddenly changes. It is a basic lecture, but it seems like it will be more understandable and helpful after watching other basic lectures, so I will watch it again later.