What is the difference between abstraction and polymorphism?

Abstraction focuses on hiding implementation details and providing a simplified view of an object. Polymorphism allows handling objects of different classes as objects of a common base class or interface, performing specific actions for each object.

Characteristic	Abstraction	Polymorphism
Essence	Hiding details, providing a general view	Ability to process objects of different types uniformly
Goal	Simplification, reducing complexity	Flexibility, extensibility, code universality
How achieved	Abstract classes, interfaces	Method overloading, method overriding, interfaces
Example	Car class without engine details	drive() method in different classes (Sedan, Truck)

Example of abstraction (using abstraction):

interface Shape {
    // Abstract method
    double calculateArea(); 
}

class Circle implements Shape {
    private double radius;

    public Circle(double radius) {
        this.radius = radius;
    }

    @Override
    public double calculateArea() {
        // Implementation details are hidden behind the interface method
        return Math.PI * radius * radius; 
    }
}

Example of polymorphism:

// Using polymorphism
Shape myShape = new Circle(5); 
// Calling calculateArea() through a reference of the base type (interface Shape)
// The calculateArea() method from the Circle class will actually be executed
double area = myShape.calculateArea(); 

System.out.println("Area: " + area);