Duplication vs. Replication
Duplication (less than 500)
Duplicated discs (often called burned discs) are made by burning tiny holes in the dye layer of a recordable CDR or DVDR. It is the same process as when you burn a disc on your home computer. This is more cost effective for small runs and takes much less time to produce.
Replication (more than 500)
Replicated discs (often called pressed discs) are made by first creating a glass master, then stampers that make exact clones using high-tech injection-molding. A coat of reflective aluminum is added and finally it gets sealed with a protective coat of lacquer hardened by ultraviolet light. Because of this extensive set up process, it is common to require a minimum of 500 discs for replication.