help please~

printf("%-8s %-8s %-12s
$%.2f\n",toll_date.c_str(),toll_time.c_str(),toll_station.c_str(),toll_charge);

what does the %-8s %-12s $%.2f mean?

and:

intf("Customer Name : %s
%s\n",customer_initial.c_str(),customer_surname.c_str());


what does the %s mean?