The flash media does not last as long as the optical media. Flash media is about the moment and will not be supported for as long.
optical
I think it is, because its an external memory.
SIC 3695 covers making optical recording media
Portable means easy to carry round, Optical means uses light to make it work. So optical media could be portable.
Only if it is a CD containing a film/something that you can watch. CDs with music aren't optical media.
Optical media include CD-ROMs, DVD ROMs, and Blu-Ray disks.
disc
The U.S. magnetic and optical recording media industry employed 20,869 people in 1997
In 2000, the U.S. magnetic and optical recording media industry employed over 36,000 people. This number has since declined due to changes in technology and consumer preferences.
CD and DVD disks are used by optical disc drives.
optical fiber