While watching the lecture, I didn't pay much attention to the table of contents, but after taking the lecture for more than halfway through, I understood each data structure through the homework that appears in each table of contents, and I realized that each data structure is related, and if you study the next part without properly understanding the previous part, you won't understand it properly. So I think it's very good to proceed according to the table of contents because you can study while drawing a learning curve in your head. I learned that the callstack, HEAP, TASK QUEUE, etc. that appeared in the event loop concept that I had skipped over because it was difficult in JavaScript mean the stack, heap, and queue that I learned in the lecture, and this lecture is the cornerstone for studying the JavaScript event loop.