Java OOPS Concept: Abstraction(abstract classes)

What is Abstraction?

Abstraction means exposing only the essential details of an object while hiding the internal implementation complexity.

Abstract Classes

An abstract class can declare abstract methods (with no implementation) that must be implemented by any subclass, alongside regular methods that already have a full implementation.

abstract class Shape {
    abstract double area();
}
class Circle extends Shape {
    double radius;
    double area() { return Math.PI * radius * radius; }
}

Why It Matters

Abstraction lets you define a common contract (like "every Shape must have an area()") while letting each specific type implement the details its own way.