function hide/override

Without virtual keyword

If the base class function is not virtual, then function call resolution is done at compile time (static binding). In this case, the function that is called depends on the type of the pointer or reference, not the actual object.

With virtual keyword

If the base class function is declared virtual, then function call resolution is done at runtime (dynamic binding). In this case, the function called depends on the actual object type, even if accessed through a base class pointer/reference.

Explicitly calling base class function