Implements vs extends: When to use? What's the difference?

Question

Please explain in an easy to understand language or a link to some article.

Answer 1

In the most simple terms extends is used to inherit from a class and implements is used to apply an interface in your class

extends:

public class Bicycle {
    //properties and methods
}
public class MountainBike extends Bicycle {
    //new properties and methods
}

implements:

public interface Relatable {
    //stuff you want to put
}
public class RectanglePlus implements Relatable {
    //your class code
}

if you still have confusion read this: https://docs.oracle.com/javase/tutorial/java/IandI/subclasses.html https://docs.oracle.com/javase/tutorial/java/IandI/usinginterface.html