Problem Statement
Give a real-world example illustrating all four major OOP principles together.
Explanation
Consider a 'Banking System'. The 'Account' class hides sensitive data through encapsulation. Different account types like 'Savings' and 'Current' inherit from 'Account'. Common methods like calculateInterest() are overridden (polymorphism). The user interacts through high-level operations such as deposit() or withdraw(), without seeing the internal logic—this is abstraction. Combining these demonstrates how OOP models real-world systems naturally.