It depends what do you mean by that. I don't think you can actually learn something just by watching other people doing it, but online courses are a good start. I started to learn programming from an online Ruby on Rails course, then I created my first website (something like 9gag) and landed my first job after a couple of months. It happend to be a small company that has later created a mobile app that we managed to scale from 0 to over 100M users. I was even a main backend guy in there for some time. So yeah, watching videos might definitely be a good start, but I'd say the actual "learning" is a long process and requires lots of attention.