Why would compiling a program which has an int main(void)
main function differ from compiling a program which has an int main(int argc,
The specification of main(...) is a contract. In the C language, the contract says that the arguments are int and char **. This is a requirement your program has to fulfill, if it wants the environment to interact with it.
Whether or not your program wants to use the parameters is a different issue -- it just has to abide by the contract that there is a functiona named main, with the correct order and type of parameters.