Interface
What is an interface according to your knowledge ? Is it a thing that a user can see ? or is it the thing we interact when we use various software applications and systems ? But "Interface" in JAVA is totally different from that. Interface is same as a class in JAVA but it is not a class. We use this concept because we haven't any way to do multiple inheritance. So that we can use "Interfaces" to inherit many classes. Like we use "extends" in classes,we use the keyword "implements" in Interfaces. Create an Interface..... interface Human { } Inherit an Interface..... eg :- class Human { } interface Man{ } class Student extends Human implements Man{ } eg :- class A{} interface C{} interface D{} interface E{} class B extends...