CD types
- Mini-CD
- CD-A
- CD ROM
- CD-R
- CD-RW
- CD + G
- VCD
According to abbreviationfinder, CD stands for Compact Disc. It is an optical digital medium used to store any type of information (audio, video, documents and other data).
The CD-ROM drive is no longer an optional accessory to become an integral part of our computer, without which we could not even install most of the software that currently exists, not to mention all the multimedia programs and games.
The disadvantages that this unit has is that at the storage level once it has been recorded on the disc then it can only be read from it, without the option to modify its content and at the reader level it is only limited to reading or playing a CD.
CD-ROM: “Compact Disk-Read Only Memory”: These disks contain information that is recorded from the moment of manufacture and can no longer be modified. CD-ROMs are the most widely used CDs for storing programs and data. Within this category you can include audio CDs, interactive CDs and all those that are already factory-recorded for various purposes (Photo CD or Video CD).
CD-R “Compact Disc Recordable”: Allows you to permanently record and store data on a CD. This type of storage is good for storing multimedia presentations, music, movies or software applications to free up hard disk space, have backup copies or move data to a different location. You can store up to 650 MB of data. They can be recorded in multiple sessions. The most notable disadvantage is that in this type information can only be recorded on each disc only once, so the added information cannot be erased or overwritten, instead the free space left by the immediately previous session must be used.
CD-RW “Compact Disc Rewritable”: Similar to a CD-R, but allows data to be overwritten as needed, so it works more or less like a floppy disk but with much more information available. It does not have a marked disadvantage, since Among the other types of CD drives, it is the most flexible since, as said, it allows recording and erasing the information on a disc, the only thing we can say is that nowadays technologies such as DVD can displace or minimize this form of storage, although its use is still valid.
Audio CD: It is the well-known CD that we listen to in a CD player for audio. We can listen to the music it contains while we work with a PC, or we can mix it in multimedia uses.
Video-CD “VCD”: For movies of this format.
CD-I: They are the initials of interactive compact disc. It is a variant of an optical disc, read exclusively on CD-ROM, which contains sound and images as well as data.
Multisession Photo-CD: The standard developed in 1990 by Phillips and Eastman Kodak specifies the procedure for converting 35mm photographs into digital signals to be recorded on a CD-R in one or more sessions. When a reel is developed, it can be requested that it be recorded in this format.
CD-XA and CD-XA Interlaced: CD’s with a mix of music and data.
DVI: It is a type of CD ROM that integrates video, television, animated graphics, multichannel audio and texts.
Cache
Most CD-ROMs usually include a small cache whose mission is to reduce the number of physical accesses to the disk. When data is accessed on the disk, it is recorded in the cache so that if we access it again, it will be taken directly from this memory, avoiding slow access to the disk. Of course, the higher the cache, the greater the speed of our equipment but there is not too much difference in speed between different equipment for this reason since this memory only prevents us from accessing the most recent data that are the ones that are being replaced within the cache those that have been around the longest and given the characteristic, in terms of volume of information, Nothing in multimedia applications prevents us from having to access the device and, as we have already explained, this is one of the determining parameters of the speed of this device. Obviously, the more cache we have the better but taking into account the price we are willing to pay for it.
