I have passed all the challenges in OOP section but I am still confused about some issues specially how all of these prinicples (object, protoype,Object.create, constructor functions,this keyword) are linked together I have reviewed this section three times and I also saw some videos on youtube ,so should I move on because the osbcurity with the time will not stay ? or should I focus on it untill I get it totally ?.
You might do well to create some practice code as examples for yourself (and possibly dig into a book or online tutorial that goes deeper into the subject).
If you can create examples that clearly demonstrate the parts you are currently unsure of then you will be ready to proceed confidently. You will also have notes to refer back to and / or share if you are helping another FCC camper.