What is a CD-R?
A CD-R (Compact Disk Recordable) is a type of CD that can be used to store a user's files inside only once using a CD recorder or a CD drive with such functionality. That is, you purchased a "blank" CD-R, and then you burned the CD using your CD drive. This "burning" meant using a laser inside your CD drive to physically alter the optical properties of the optical disk according to the data that was being stored. The CD-R could only be burned once due to its physical properties.
If the CD drive failed to burn the data successfully, the CD-R would be rendered useless, and you would have to try again with a new CD-R.
