A CD-R is a type of disc that does not contain any data. It is blank so that a user can write their own data to the disk for various purposes, such as storage and backup. An improved version of that is the CD-RW, which is a disc that can be written to multiple times. The user can erase the contents of the disk or write new data whenever they want, just like older floppy disk technology.
CD-R was created to be compatible with all devices that use the same medium, although the method of writing data to the disc differs slightly compared to traditional CDs. CD-R was also known as “Write Once, Read Many” due to the fact that you can only write to the disc once. This can be a bit confusing as you can actually write to a CD-R multiple times as it allows you to write to the disc in increments. The CD-R medium also produced its own disc. The CD Writer is a drive that looks and acts like a normal CD-ROM but with the ability to write data to CD-R.
What it does on a CD-R is erase the old data and replace it with a new one. Once the disk is full, you cannot add or replace data on it. That deficiency has been remedied by the advent of CD-RW discs. These discs are very similar to CD-Rs but have the added feature of being erasable. Erasing the data on a CD-RW disc returns it to its previous state and can be used as a blank disc. CD-RW technology requires much better optical technologies than CD-R requires, so CD recorders cannot write to CD-RW. Although backwards compatibility means that all CD writers and some of the older CD-ROMs can read a written CD-RW.
CD-Rs have some advantages over CD-RW, one of which is the fact that the former costs much less compared to the latter. CD-Rs are also much more reliable for storing data due to the unstable nature of the alloy used in CD-RWs. Read and write times are also significantly higher on CD-RWs, causing longer wait times for the user. With those arguments, CD-Rs and CD-RWs are about the same even when weighed. CD-Rs are suitable for storing data for long periods of time, such as backups, while CD-RWs are excellent for transferring files from one PC to another for reuse.