It sounds like you're referring to the popular by Jonas Schmedtmann on Udemy.
Jonas Schmedtmann’s course distinguishes itself by treating as a primary subject, rather than an afterthought. It sounds like you're referring to the popular
By the end of this course, you'll be able to: the Call Stack
Instead of just saying "use fetch to get data," Jonas uses visual animations to explain the , the Call Stack , and the Microtask Queue . and the Microtask Queue .