Why's this happening?

[The illusionist mirage]

Hello

I was programming something when I noticed that I can do this:

.
.
int main()
{
    blaseClass *baseObjPtr = nullptr;
    childClass childObject(12, 'a');
    baseObjPtr = &childObject;
.
.
}

where baseClass is:

class baseClass{
    private:
        int base_value;
    public:
        void putValue(int VAL)
        {
            base_value = VAL;
            std::cout << "base_value = " << base_value << std::endl;
        }
};

and childClass is:

class childClass : public baseClass{
    private:
        int child_value;
        char child_char;
    public:
        childClass(int VAL, char CH)
        {
            child_value = VAL;
            child_char = CH;
            std::cout << "child_value = " << child_value;
            std::cout << ", child_char = " << child_char << std::endl;
        }
};

Why's this happening? Why am I able to use a pointer of some type with an object of another type?

Thanks

[MikeyBoy]

Look up polymorphism. It's one of the foundations of Object-Oriented Programming.

[The illusionist mirage]

Ok, I'll look it up. Thanks.

EDIT:
Though I've done OOP, neither my course materials nor my teacher ever mentioned anything related to polymorphism.