What is a virtual function

Answer 1

In object-oriented programming, in languages such as C++, a virtual function or virtual method is an inheritable and overridable function or method for which dynamic dispatch is facilitated. This concept is an important part of the (runtime) polymorphismportion of object-oriented programming (OOP).

-wikipedia

Answer 2

A virtual function is a member function that you expect to be redefined in derived classes. When you refer to a derived class object using a pointer or a reference to the base class, you can call a virtual function for that object and execute the derived class's version of the function.