I started with only Java basics without knowing anything about the framework. At first, the membership service was just an algorithm. To be honest, it was okay because I had some basic knowledge, but it wasn't easy to understand the membership algorithm. It was complicated.ㅠㅠ However, I focused on each one and looked at it again, and I understood it. I'm currently stopping in the middle and going to another lecture, but I plan to come back and study after I finish that lecture. Thank you for the great lecture. I'll come back after listening to the teacher's MVC and basic lectures.