Fractional reserve banking system as the name says it is a way in which a bank gives the opportunity to the people to loan the bank with the difference of having an advantage of earning a percentage of the money they put at the beginning. first we have to example that mostly all the money a country has doesnt exist , their is no physical representation of this money. In USA 97% of the money is digital. mostly all the money loan s digital from one account to another .

The video of Fractional reserve banking system  show as that the money has some value because the goverment and the same people give it . if they didnt do that it would just be a munch of paper. People decide to put their money in a bank because each time the bank lends money they use the same money of the people using their service. for example i put one hundred dollars in an account . what the banks do is they take omeny from my account so im loaning the bank , they only can take me 90% of my money letting a 10% there. then the bank will give me bank my money but giving an extra money . This is in someway how the Fractional reserve banking system works. Hope you understand.