After listening to the Java basics lecture and the Spring introductory course, I didn't understand the post mapping and get mapping related to the web, so I took the HTTP course before moving on to the Spring core principles. Unlike the Java and Spring lectures, there isn't much practical content, so I'm worried that I'll forget it quickly, but I think I understand the meaning of what I just wrote when I was learning Spring. I feel confident enough to take the core principles lecture! I'll review the introductory code and see you in the next lecture. Thank you for the great lecture.