Short for
Copy Guard Management System, CGMS is a method of
copy protection used to prevent unauthorized
disc copying. The Copy Guard Management System first determines if
data recorded on a recording medium is original or copied, and then prevents the data from being copied when it is not original. A copy of the original can be made only once, but a copy of data (secondary copy) cannot be copied again. May also be called
Single Copy Management System (SCMS).