I read 3-4 books related to Spring, and most of them only described simple definitions and usage of AOP. So I didn't understand how AOP works and what each term meant, but after listening to Younghan's lecture, I think I was able to understand more clearly how AOP works and what each term meant. While listening to the lecture, I was amazed at how you organized the curriculum and explained it so well. You have helped me a lot by making many good lectures, and I will continue to ask for your help in the future. Thank you very much!!