CD copiers or CD duplicators copy the contents of one CD into another CD or CDs. Copiers can work in conjunction with computers, or they may be standalone. Standalone copiers work independently without the assistance of a computer. CD copiers can be used to copy all types of CDs - CD-ROMs, DVDs, video as well as audio.

Contents of an original CD, called the master CD are copied onto blank CDs. A CD copier can copy contents onto several blank CDs at the same time. Earlier models required a someone to keep changing the CDs as each got copied; but newer copiers are automated. These can take CDs one after the other.

CD copiers may be CD-writable (CD-R) or CD-rewritable (CD-RW). In CD-Rs, a laser recorder copies data onto the blank by selectively burning an organic dye on the CD surface. This process is also called burning and it is a permanent and irreversible process. CDs copied by a CD-R can be used only once. But in CD-RWs, a laser recorder melts an alloy on the surface of the CD in selective degrees. This is a reversible process and these CDs can be used for a thousand rewrites.

CD copiers may be manual, integrated and networked. Manual CD copiers require the operator to physically open the copier and reload the CDs. They are slow, and can copy only one to 9 CDs at a time. Their speeds can range from 8 times to 52 times. Integrated CD copiers have a USB drive, which can be connected to the USB port of a computer. This can speed up the copying process.

Automatic CD copiers are also called standalones. They have a robot arm which can load and unload CDs. Standalone CD copiers are actually a combination of many CD copiers, as many as 16. Thus, a large number of CDs can be copied at a time-from 100 to 1000. CDs that cannot be copied are automatically rejected at the end of the process.

CD copiers are often used by companies to make CDs of their presentations or seminars. Music and movie companies also use copiers to manufacture CDs in bulk.