Whether it is a DVD-RW or a CD-RW, the technology format is the same.

RW on the end of a media title stands for Rewritable. This means that a computer user can add files to the disc, delete those files and add more files in mulitple settings. An RW disc, again, CD or DVD, can be reused over and over again. Whereas, an R is slightly different.

R on the end of a media title stands for Recordable. This means that a computer user can add files to the disc only once. These files cannot be deleted or the disc reused. Once the file are on an recordable disc, they're there for good.