Well, you are not supposed to know all of them by heart. just start by what you need and know what other technologies that exist so you can learn them when the need arises. for me, I think I know or have a vague idea about most of the concepts mentioned in Frontend and Backend. But DevOps sections seems intimidating to me. People in other fields might feel the same way about Frontend or Backend Development. The thing is, just like any craft, it requires time and practice.