Either you are a beginner or a professional in Java programming language, you must have come across the term Java Interface. As a beginner, if not, actually you have not learnt the Java language properly. Even you may not be a good Java Programmer, if you have not learnt each aspect of a Java Interface. You are expected to know about Java Interface in a deeper way. Additionally, what are the changes introduced in newer versions of JDK, especially in JDK8. For example, the introduction of default and static methods in Java Interface. Needless so say, the introduction of new features in Java 8 has completely changed the definition of Java Interface. Before Java 8, no method with a body was