What should be returned from a C main function? EXIT_SUCCESS or 0?

Question

What actually should be returned from C main function? I am confused whether to return EXIT_SUCCESS or 0 since different sources point different views.

When I try the two I seems to get the same output.

int main(void){
   return EXIT_SUCCESS;
}

int main(void){
   return 0;
}

What is the use of either one and where should I use each?