Invoking the Base class constructor from the Derived Class

[Anmol444]

I understand it is done like this

// Calling the base class constructor
explicit CCandyBox(double lv, double wv, double hv, const char* str="Candy"): CBox(lv, wv, hv)
{
...
}

But how does the compiler know that you are initializing the base "part" of the object?

Or is this the entire reason initialization lists exist, to separate this confusion?