I followed the youtube tutorial and i can create basic class but the tutorial doesn't explain how the Class::Class works, I search google but i only know that it is called unary operator and what it does but I dunno what it do with Class, please help me explain about this and thanks very much.

```
#include <iostream>
#include <string>

//Class
class Mother {

    public:
        void msg();

};

void Mother::msg(){ //This is where i don't undrstand
    std::cout << "Go home early sweetie" << std::endl;
}

class Daughter: public Mother {

    public:
        void getMsg();

};

void Daughter::getMsg(){ //Same as this
    std::cout << "Mom said ";
    msg();
}

//Main
int main() {

    Daughter lucy;
    lucy.getMsg();

    return 0;
}

```