Not able to understang this concept of handlers in c++

I was going through a piece of code where I came across something new.However I tried to write my own code for better understanding.

#include<iostream>

using namespace std;

class material
{
public:
material()
{
    cout<<"material() called"<<endl;
}

bool test_func()
{
    cout<<"Hello World"<<endl;

    return true;
}
};

class server
{
private:
material *mat;

public:
server()
{
    cout<<"server() called"<<endl;
}
material *matrl()
{
    return mat;
}
};

class Handler
{
public:
Handler()
{
    cout<<"Handler() called"<<endl;
}

server svr;

bool demo()
{
    bool ret;
    ret=svr.matrl()->test_func();

    return ret;
}
};

int main()
{
Handler h;
cout<<"returned by demo():"<<h.demo()<<endl;

return 0;
}

Even I am getting the desired output, which is:

server() called
Handler() called
Hello World
returned by demo():1

But I am not able to understand certain concepte over here,like

material *matrl()
{
    return mat;
}

and the call

ret=svr.matrl()->test_func();

How this is working and what concept is this.Can somebody help me with this???