Final answer:
The main advantage of CD-RW over CD-R is its reusability. You can erase and rewrite data on a CD-RW, whereas a CD-R allows data to be written only once. Blue light lasers can store more data due to their shorter wavelengths.
Step-by-step explanation:
The basic advantage of using CD-RW over CD-R is the ability to rewrite data. A CD-R (Compact Disc-Recordable) allows you to burn data onto the disc only once. Once the information is written, it cannot be erased or modified. In contrast, a CD-RW (Compact Disc-ReWritable) can be written on multiple times. You can erase the data on a CD-RW and rewrite new data onto it, making it more versatile if you need to update or change the information stored.
CDs store information digitally by having pits made in the CD surface by a laser. This digital pattern can be read by an inexpensive solid-state infrared laser as the CD spins. However, a laser that emits blue light can burn and read more information than an infrared one because the shorter wavelength of blue light allows for more precise and closer pit spacing. This enables greater storage capacity on the disc.