How does overloading work in a program?

Question

C++ / C#

Hello, kind people
Correct me if I'm wrong: overloading is a predefinition for classes of the existing designation of operations, as a result of class overloading, you can use the operation values ​​familiar to base types.
A predefined function is a function, which means it can be overloaded, that is, create several functions with the same name, but different input parameters.
This is a scientific notation, but I understand it like this - when we perform operations on classes, the compiler does not know what to do, and we explicitly indicate what operations should be performed when calling the operator. - Do I understand correctly, or not?
Please explain how values ​​are passed to overload in this program.
What does kvad mean here, and if you specify k*kvad when calling, then the overload will be called float operator *(float k,kvadrat a) - Right?

#include <iostream>

class Kvadrat{
private:
  float storona;
public:
  Kvadrat(float a){
    storona = a;
  }

  float ploshad(){
    float S = storona*storona;
    return S;
  }

  float operator * (float k){
    float S = storona*storona*k*k;
    return S;
  }
};

int main(){
  float a, k;
  printf("Vvedite storonu kvadrata: \n");
  scanf("%f", &a);
  Kvadrat kvad(a);
  printf("Ploshad kvadrata: %f\n", kvad.ploshad());
  printf("Vvedite koef podobia: \n");
  scanf("%f", &k);
  printf("Podobniy kvadrat: %f\n", kvad*k);
  getchar();

  return 0;
}

Answer 1

Your operator* is overloaded incorrectly - it must return an object or a reference to an object of its class (i.e. it must return Kvadrat&): https://en.cppreference.com/w/cpp/language/operators
Parameters are not passed to the overload , but into a function or method (overloaded operators are a special case of a method).
For binary operators, the overloaded operator is called for the class on the left in the expression. For example, for kvad * k - kvad.operator*(k) will be called.
If you write k * kvad, then there will be a compilation error, because the compiler will not be able to convert kvad to float. But you can help by overloading operator float() for Kvadrat.