CD duplicators or compact disc (CD) copiers copy the content from one CD onto other CD (or many other CDs). These CD copiers can be integrated, networked or manual. When using manual CD copiers, the operator needs to individually open the copier in order to reload the CDs. However, the drawback of manual CD copiers is that they are very slow and can only copy 1-9 CDs at a time. Due to this, manual CD copiers are generally used by small duplication companies.On the other hand, the high-end versions of CD copiers let the operator easily copy CDs in bulk so that one can easily copy up to 1,100 CDs at the same time. CD copiers can be CD-rewritable (CD-RW) or CD-writable (CD-R). When copying data on CDs, a laser recorder is used to copy data to a blank CD by burning an organic dye onto the surface of the CD. This process of copying data is popularly known as burning and is an irreversible and permanent process.On the other hand, when copying data on CD-RWs, a laser recorder melts an alloy on the CD surface in selective degrees. This is a reversible process and the data from the CD-RWs can be erased and rewritten a specific number of times. Bulk CD copying is another process that can prove to be very useful for music companies that require numerous copies of their data for distribution purposes.