What is the difference between a DYS bulb and a standard PAR bulb?

A DYS designated PAR can bulb means that it corresponds to a code set by the American National Standards Institute (ANSI). A bulb that corresponds to ANSI bulbs will meet identical specifications regardless of the manufacturer. A DYS coded bulb is a 600w glass halogen bulb with a GY9.5 base. It has a color temperature of 3,250K and a rated life of 75 hours.