Only address or entire function is passed when we pass function as an argument?

Question

I have been using JavaScript for quite sometime but this question keeps coming back to me every now and then. Consider the following code snippet :

function dummyFunc(inputFunc){
    return inputFunc();
}

function getNumber{
    return 100;
}

dummyFunc(getNumber);

When am passing getNumber - only the address of function gets passed or entire function declaration gets passed to dummyFunc ?

If this is answered already please let me know ?