s cheap.… first ones are those that cover the “width” while the second one are those that cover the “depth”. For example, Udacity courses cover the width. They will teach you almost all the aspects but none of them will be covered in depth. On the other hand, coursera courses are great if you are looking to deep dive into some aspects but they won’t cover every element required. This the major bottleneck today. Finding all the things that are required to learn in a single place is a bit difficult when it comes to an online course. Plus nothing is cheap. Online courses are not that expensive as Masters but they are expensive.