Question

Let's begin by discussing how an interface class differs from a concrete class, how interface classes are defined, and what does implementing an interface class mean!

Answer 1

Interfaces means 100% abstraction.
Interfaces doesn't implement any method.

If we want to implement the methods in the interface then
we have to create a class that implements the interface.

Then in this class we should have to implement all the methods
mentioned in the iterface.

Example (Java):
---------------
interface shape{
    void printShape();
}

class circle implements shape{
    void printShape(){
        System.out.println("Circle")
    }
}