C++ has a unique functionality which allows for multiple functions to be declared with the same function name. This is useful when different data types need to be manipulated in similar ways. This is best shown by example.

#include <iostream>
using namespace std;

int sumFunc(int x, int y) {
  return x + y;
}

double sumFunc(double x, double y) {
  return x + y;
}

int main() {
  int sumInt       = sumFunc(13 , 7);
  double sumDouble = sumFunc(3.1, 7.342);

  cout << "Int: "    << sumInt    << "\n";
  cout << "Double: " << sumDouble << "\n";
  return 0;
}
// Int: 20
// Double: 10.442

In the example above, a function plusFunc() is defined with arguments of type integer and a return value of type integer, as well as arguments of type double and a return value of type double. The version of the function that ultimately gets executed depends on the data types that were passed as arguments.