Today's mission involves using multiple Object-Oriented Programming (OOP) principles to tackle complex tasks. When principles like Encapsulation, Abstraction, Polymorphism, and Composition are blended, the resulting code becomes streamlined and easier to manage.

Our goal is to dissect two real-world examples, gaining insights into how these principles can seamlessly orchestrate solutions.

Let's design an online library system to reinforce our understanding of Encapsulation and Polymorphism. Encapsulation will help us protect the attributes of books, members, and transactions, ensuring they are accessible in a controlled manner. Polymorphism will demonstrate its power by enabling a single interface to represent different underlying forms, such as digital and print versions of books.