March 30, 2001

Q: Is a DVD like a CD?
A: In many ways, the process is similar, but there are some differences.
The DVD disc is made of two layers. So when they’re bonded together they
are as thick as a CD (1.2 mm). The pits of a DVD disc are not as big,
and much more closely spaced, than those of a CD. That means the laser
that "reads" the disc must be smaller.