I agree, my terms aren’t perfect, but as you stated there isn’t really such a thing as an interface in c++, traditionally this is achieved via an abstract base class which is what I meant by using them interchangeably.

I know there are many things you can do in c++ to enforce an interface, but tying this back to the original comment that inheritance is objectively bad, I don’t think there’s any consensus that this is true. Abstract base classes (with no data members) and CRTP are both common use cases of inheritance in modern C++ codebases and are generally considered good design patterns.