Hello, learner! In today's exciting chapter, we will unravel Polymorphism, a prominent feature of Object-Oriented Programming (OOP). Specifically, we will study its role in maintaining backward compatibility while introducing new features. Think of it as a software update that introduces new functions without breaking the older functionality — ingenious, isn't it?

Polymorphism, a principle derived from the Greek words 'poly' (many) and 'morphism' (forms), enables a variable or method to assume multiple roles — to embody various behaviors or functions determined by its data type or class.

Consider a class Bird with a method can_fly. If we create subclasses like Sparrow, Penguin, and Ostrich, we can override the can_fly method for certain subclasses. This demonstrates polymorphism in action.

When adding new features, which introduce new behaviors to some components, polymorphism ensures that the existing parts function as before, thereby retaining backward compatibility. In complex cases, we maintain an older version of the method in the superclass for legacy support while offering newer functionalities in subclasses.