S.O.L.I.D.

 Solid Principal Aims at designing application architecture in such a way so any new change made to application will not induce any defect

S - Single Responsibility

O - Open and Close Principal  - Abstract class could be extended without breaking or changing existing code

L - Liskov Substitution Principle - Ensure subclass follow contract of parent class using Inheritence.

I - Interface Segregation Principal - Use Mulitple Interfaces instead of Single Large Interface

D - Dependency Inversion Principal - Use Dependency Injection and Interfaces to Depend on Abstraction.

Example to demonstrate Liskov

abstract class Vehicle {

    abstract void start();

}

class Car extends Vehicle {

    @Override

    void start() {

        System.out.println("Car is starting...");

    }

}

public class Main {

    public static void main(String[] args) {

        Vehicle myCar = new Car();

        myCar.start();

    }

}

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