hlp.......v.2?

Question

What are the two characteristics give a DVD disk more storage capacity that than a CD disk?

and

How does the UDF file system apply to a DVD?(i already found the use of the file system, but i dont know the second part)

Answer 1

The DVD uses a different laser with a smaller wavelength, not the long wavelength red laser that is used for CD's. I believe the DVD laser is in the ultraviolet spectrum. Anywho, the smaller laser allows the DVD to have smaller "bumps" (which is what the laser reads). Since they are smaller, more can fit onto a disk. Also, DVD's can be 2-layer. Twice the data.