"throws" is used when declaring a method which may result in an exception where the method itself does not
handle the exception using try/catch.
Details at Lesson: Exceptions (The Java™ Tutorials > Essential Classes)
Whether you decide to handle an exception in the method where it occurs or in the caller of the method (or somewhere higher up the call chain) is a matter of design. You have the choice: handle an exception right where it occurs (with try/catch), or have the caller handle it (with throws).