CORS Explained
CORS is a concept that I used to struggle to understand, probably because it is one of those things you typically only run into when it causes you problems and you typically try to solve it just so you can get on with what you were originally trying to do. I understand it well now but this video showed up in my feed and it does a good job explaining it.
LearnThatStack has been consistently release great videos that explain a number of software development concepts. I would definitely recommend subscribing and sharing their content with others.