Explain the differences between interface and class in Java
Interface has no implementation where class provides implementation for interface (its own or some external; if class implements one it has to provide implementation for it) This is very very important questions and probably the first Java question that will be asked to your by interviewer.
interface vs class
interfaces r non implemented they have by default abstract public methods
any one who wants those methods they can implement .
but in class they r implemented class itself they r not usefule to general purpose means abstacted way.