JavaScript JavaScript and the DOM Responding to User Interaction The Event Object

I think the teacher Guil Hernandez should includ a brief explanation of the most important concepts in the lecture notes

I don't think I'm the only one who wants that. I understand there's the MDN, but he as a teacher could make it more 'easy' for students if he types an explanation. I hope this serves for future videos.

PD: He does this in some videos, but not all. And in the videos he doesn't, it is very confusing the concept.