what is make function in cpp code example

Example 1: functions in C++

void Hello() {
  std::cout << "Hello";
}

int main () {
  Hello();
}

Example 2: how to make a function in cpp

// function returning the max between two numbers
 
int max(int num1, int num2) {
   // local variable declaration
   int result;
 
   if (num1 > num2)
      result = num1;
   else
      result = num2;
 
   return result; 
}