ELI5: Explain Like I'm 5

Optical disc

Optical discs are circular discs that store data like music and videos when you put them in a special player. They look like shiny CDs or DVDs. The data is stored using tiny bumps and ridges on the disc that a player can pick up and read. The player uses these bump and ridges to figure out what kind of data is on the disc, so it can play music or show a video on your TV.
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