Java Encapsulation and Visibility: Protecting Object State with Access Modifiers

The article explains how encapsulation and visibility in Java help developers control how objects are used, not just whether code works. It uses a BankAccount class as an example, where the balance field is private so it cannot be changed directly from outside the class. Methods are given different access levels: public for deposits and withdrawals, package-private for applying fees within the same package, and protected for subclasses and same-package classes. A private method, resetBalance, is shown as an internal implementation detail hidden from other code. Together, these modifiers protect the object's data and limit how the class can be used.