This lesson introduces functional interfaces, which are the foundation of Java's functional programming features like lambdas and streams. You'll learn what they are, how they work, and how to use built-in types like Predicate, Function, Consumer, and Supplier.

This lesson introduces Java Streams, a modern way to process collections functionally. You'll learn what streams are, why they're useful, and how they compare to traditional loops.

In this lesson, you’ll learn the difference between inheritance (an "is-a" relationship) and composition (a "has-a" relationship), and when to use each. Understanding these concepts helps you design more flexible, maintainable, and decoupled systems.

In this lesson, you'll learn how the Object class—the root of Java’s class hierarchy—provides core methods like toString(), equals(), and hashCode(). You’ll also understand how and why to override these methods to make your classes more useful and readable.

In this lesson, you’ll learn what constructors are, how they work in Java, and how to use constructor overloading to give your classes more flexibility when creating objects.

In this lesson, you’ll learn about Abstraction, a core principle of Object-Oriented Programming. Abstraction helps hide internal implementation details and exposes only the essential behavior of an object.

In this lesson, you'll explore Polymorphism, a powerful concept in Java OOP that allows objects to take many forms. Polymorphism enables flexible code that can work with different object types through a common interface or superclass.

In this lesson, you’ll learn about Inheritance, one of the key pillars of Object-Oriented Programming. Java allows one class to inherit from another, enabling code reuse, extension of functionality, and hierarchical relationships between objects.

In this lesson, we’ll explore Encapsulation, one of the core pillars of Object-Oriented Programming. You’ll learn how to hide data, control access, and safely expose object behavior