With out getting into if perl is compiled or not the differenct between a complite time error and a run time error is very simular to that of C.

A compile time error is one the keep perl from being able to parse the file; such as a missing semi-colon. And a run time error is an error that can not be detected untill the code is run; such as a divide by zero error or a call to an undefined subroutine.