knowledge hierarchy or structure

Another things I need to mention: you need a perfect knowledge structure. Knowledge or technolodge are the same. People need it to some problem. Althought some times it seems complex, the core design idea is simple. Some talented guys have to describe it . They are likely to make it complex like redux. For example, bootstrap make multiple classes that you can call. When you need them, just simply call it. Althought the name of these classes looks tedious