The explanations and examples in the lectures are of low quality, and when you organize the content, there are many contents that do not fit the context and the explanations are not accurate. If you just look at the explanations written in the comments, you cannot understand what they mean. In the end, you have to go back and organize the content and study, so there are many regrettable points... If you are completely ignorant about threads, it may be helpful, but I wonder if the difficulty level is intermediate or higher...