I finally finished the basics course following the introductory course in Java. I was so excited to listen to the lecture because I felt like I understood it because the explanations were so good. If it weren't for Professor Yeong-Han, I don't think I would have understood concepts like object-oriented, reference type, and polymorphism. I realized once again that this is the best course in the development field. Thank you for giving such great lectures! I will listen to Spring while studying other subjects until the intermediate and advanced courses come out. Thank you!