[Oracle interview]What are Checked and UnChecked Exception?

A checked  exception is some subclass of Exception (or Exception itself), excluding  class RuntimeException and its subclasses.Making an exception checked forces  client programmers to deal with the possibility that the exception will be  thrown. eg, IOException thrown by java.io.FileInputStream's read()  method?       Unchecked exceptions are  RuntimeException and any of its subclasses. Class Error and its subclasses  also are unchecked. With an unchecked exception, however, the compiler  doesn't force client programmers either to catch theexception or declare it  in a throws clause. In fact, client programmers may not even know that the  exception could be thrown. eg, StringIndexOutOfBoundsException thrown by  String's charAt() method? Checked exceptions must be caught at compile time.  Runtime exceptions do not need to be. Errors often cannot be.