relationship between *this and function members

Person.cpp

#include "Person.h"
#include <iostream>
#include <string>

/// implementation section

Person::Person (std::string n, std::string a) :
                name (n), address (a) {}

const Person &Person::display () const
{
    std::cout << "const version func is called " << std::endl;
    return *this;
}

Person &Person::display ()
{
    std::cout << "non const version func is called " << std::endl;
    return *this;
}

Person.h

#ifndef PERSON_H
#define PERSON_H

#include <iostream>
#include <string>

class Person
{
public:
    Person () = default; /// here we declared a default constructor
    Person (std::string, std::string); /// we declared a second constructor for initialization

    const Person &display () const; /// we declare a const function member that returns a reference to const object
    Person &display (); /// we declare a non-const function member that returns a reference to object

private:
    std::string name, address; /// data members to hold
};
#endif // PERSON_H

rbtf.cpp

#include <iostream>
#include "Person.h"

int main()
{
    Person p1;

    p1.display().display(); /// this calls the non-const function member of display because the object is non-const which is the *this is default
                            /// initialize into non-const pointer of *this and we need a member function that have non-const pointer which is a
                            /// non-const function member of display and returns a reference to object and calls again a display if it doesnt
                            /// if a return is not a reference to an object a copy of an object will be return not the actual object

    const Person p2;
    p2.display().display(); /// this calls the const function member of display 

    return 0;
}