Working as a front-end developer in the field, I always felt that I lacked knowledge of networks when it came to understanding infrastructure elements. Recently, I felt a strong need to understand basic network concepts such as bandwidth, latency, and packet loss during performance testing and reflect them in the test to more accurately evaluate and improve web performance. This lecture was very helpful because I was able to go over the overall flow of client requests and server-side data processing in just 3 hours through real-life cases and easy analogies. In particular, I thought that only JavaScript dealt with the web, but it was new to me that Python also provides various libraries for processing client requests. This lecture was like reading a thick network textbook in just 3 hours, and it was a great help in quickly understanding the core concepts. I am interested in studying AI these days, and I think this network knowledge will be a great help in developing AI web applications using Python. In particular, when preparing for an interview in a short period of time, it is very attractive to be able to organize key terms and concepts in just 3 hours. This lecture will be of great help to those preparing for employment or those who want to organize network concepts in practice.