Answer -   An interface is a structure of code which is similar to a class. An interface is a prototype for a class and is useful from a logical design perspective. Interfaces provide a means to define the protocols for a class without worrying about the implementation details. The syntax for creating interfaces follows: interface Identifier {   InterfaceBody } Identifier is the name of the interface and InterfaceBody refers to the abstract methods and static final variables that make up the interface. Because it is assumed that all the methods in an interface are abstract, it isn't necessary to use the abstract keyword An interface is a description of some of the members available from a class. In practice, the syntax typically looks similar to a class definition, except that there's no code defined for the methods — just their name, the arguments passed and the type of the value returned. So what good is it? None by itself. But you create an interface so that classes will implement it. But what does it mean to implement an interface. The interface acts as a contract or promise. If a class implements an interface,