CDs and DVDs are manufactured using 2 distinct processes. The first, commonly referred to as CD Duplication or Short-Runs uses multiple recorders linked together to reproduce your master onto CDRs or DVDRs. There’s no intermediate steps and the turnaround is very fast (2 to 3 days). It’s your only option on orders fewer than 300 units.
The second process usually referred to as CD Replication goes through additional steps and the turnaround is slower (15 days). A “glass master” (you can think of it as a stamp) is made from your master, and used to replicate your CD or DVD. It’s a cost effective solution on large orders or if you plan to re-run your job in the future.