This is a very detailed and good lecture. It explains the overall structure of Spring Security and the flow while looking at the actual internal code, so you can learn how it works. When I first listened to it, I didn't really understand the content because of the details, but after looking at it once, I applied it to my project for the second time, and after looking at it for the third time, I was able to feel the true value of this lecture. As I continued to modify the structure to make authentication and authorization work properly in the project, I was able to roughly feel the flow of the code, and after looking at this lecture again, I felt like I could see the overall structure and specific flow of Spring Security at a glance. I haven't been able to utilize all the functions yet, but I plan to refer to this lecture whenever I need to. Thank you for the quality lecture.