Writable CDs don’t store data on microscopic holes, they instead have a layer of pigment that changes color when heated by a laser.

“The writing process does not produce indentations (pits);” en.wikipedia.org/wiki/CD-R#:~:text=The writing pr…

CD-RWs have a coating that can change to its original when the laser heats it to a specific temperature (high heat to write, low heat to erase)

“To erase the disc, the write beam heats the amorphous regions with low power to about 200 °C.” en.wikipedia.org/wiki/CD-RW#:~:text=To erase the ….