Java exceptions fall into two categories, called checked and unchecked exceptions. When you call a method that throws a checked exception, the compiler checks that you don't ignore it. You must tell the compiler what you are going to do about the exception if it is ever thrown. […] On the other hand, the compiler does not require you to keep track of unchecked exceptions. […] A checked exception describes a problem that is likely to occur at times, no matter how careful you are. The unchecked exceptions, on the other hand, are your fault.