void f2(int argv[3]) {
  //here argv is a variable containing an address
  //argv[0] == *argv;
  //I can also say ++argv;
}
void f3(int *argv)
void f () {
  char argv[3]; //argv==&argv[0]. can't assign to this argv.
  //char *argv;   /argv is a place containing an address. can even assign to it.
  f2(argv); //the address, so far not stored anywhere, is copied into f2's var
}

----
conclusion:

Inside a function, a local variable char x[] is different from char *x, which can also be assigned to.

In a function signature, the only thing is char *x. char x[] is only for documentation purposes. It tells you that besides x, x+n is also possibly a valid pointer.

int main(int argc, char **argv) {
}