Can you guys explain how my fuel pump works please?

How do my fuel pump keep on pumping fuel to my injectors. Is there something to reset after fiting a new pump cause my fuel pump just stops pumping then after a few hours I can start it again. The thing is they jump strarted my car but reverse the cables is ther something that could have been damage cause just after that it started doing that. I checked all fuses or could it be the relay that's damage. I need help urgently cause my car is in everyday use.