A checked exection is any exception that is expected to be handled by the developer. If your compiler complains that an exception isn't handled in your code, then the exception you aren't handling is a checked exception. The compiler is 'checking' to see if you handled it in your code. Runtime exceptions are not checked. The compiler doesn't EXPECT you to handle them however you can catch them if you want.
By failing to prepare, you are preparing to fail.<br />Benjamin Franklin (1706 - 1790)