CDR vs CD ROM
People have always used data storage devices to store music, games, and other information or data. While before we record music on magnetic tapes, today we do it by using digital compact discs, the most common of which are CDR and CD ROM.
CDR (Compact Disc ï¿½ Recordable)
CDR is a pre-manufactured blank compact disc wherein data can be recorded or burned. It was first developed by Philips and Sony. Most CDRs have 80 minute capacities but some can contain longer data. CDRs can be used until their memories are full or finalized. They can only be read after they are finalized and any data that have been burned cannot be deleted.
Data is stored in a special dye layer and then burned with laser creating pits and lands that can be read by a CD drive and converted into digital 1s and 0s. Data can be written on the CD using these methods:
ï¿½ Disc At Once, wherein data is written on the CD in one session with no gaps making it a read-only CD.
ï¿½ Track At Once, wherein data is written one at a time and the CD is left open for further input.
ï¿½ Packet Writing, wherein data is recorded in several sessions allowing the user to add data at a later time.
It is a WORM or Write Once Read Many optical medium and it is compatible with standard CD readers. It is suited for small runs of CDs which only require quick turns. CDRs have a limited lifespan; the dye can degrade after a few years making data unreadable.
CD ROM (Compact Disc ï¿½Read Only Memory)
CD ROM is a manufactured compact disc wherein data is already stored with the pits and lands already pressed or molded into the polycarbonate base by using a stamper. It is read only and is suitable for large runs.
CD ROMs cannot be written on and cannot be burned. Every data stored in them are already pressed into the discs which can be read by digital devices like CD players and PC or CD ROM drives.
They are being used to distribute computer software, games, and multimedia applications. Software distributors especially those of computer games employ copy protection schemes to limit the running of their software to the original CD Rom only.
1. Compact Disc ï¿½ Readable is a pre manufactured blank compact disc wherein data can be written and recorded while Compact Disc Read Only Memory is a manufactured compact disc with data already stored.
2. Data on the Compact Disc ï¿½ Readable can only be read after it is finalized while data on a Compact Disc Read Only Memory can already be read upon purchase.
3. Both can be read using any digital device but Compact Disc Readable is suited for small runs while Compact Disc Read Only Memory is suitable for large runs.
4. Compact Disc Readable can be written on or can be burned while Compact Disc Read Only Memory cannot.
5. Compact Disc Readable is used by those who want to record something while Compact Disc Read Only Memory is used by those who want pre recorded games or music.