PROM (Programmable Read-Only Memory) is not an example of an optical disk.
Optical Disks:
These store data using patterns of pits and lands on a reflective surface, read by a laser. Examples include CD-ROM, DVD, and Blu-ray Disc.
PROM:
This is a type of semiconductor memory chip. It's a form of ROM (Read-Only Memory) that can be programmed once after it's manufactured. The data is then permanent and cannot be changed. PROM uses electrical signals to store data by permanently altering the internal structure of the chip (e.g., by blowing fuses).
Therefore, PROM is a type of memory chip, while CD-ROM, DVD, and Blu-ray are optical storage media.
