This is a lecture recommended to those who want to learn JavaScript ' seriously'. This was a great lecture for me, who was trying to learn JavaScript in earnest after seeing and hearing about it here and there, and using it in passing. Rather than learning JavaScript from the beginning by reading the MDN document, it would be great to listen to Code Factory's <free> Introduction to JavaScript and study advanced concepts. I think I learned really essential and core content concisely and easily. I enjoyed the lecture. Thank you.