Demonstrates the usage of Interfaces and its principles. This repository includes the implementation of :

• Interfaces : - We use interfaces to build loosely coupled, extensible and testable applications. They are similar to class but only include method declaration and no implementation.
• Interface methods : Methods declared inside interfaces are by default public and abstract. We can't declare them static or final.
• Interface states : Variables declared inside interfaces are by default public, static and final.
• To have intefaces in action we make use of dependency injection.(Subtypes : Constructor, Setter and Method Injection respt.)