CDs seem like a relic from the past.
After all, we're much more likely to listen to music on our smartphones - why would we bother with the faff of a CD? That's a compact disc, in case you didn't know.
They might be old school, but the tech behind a CD is still pretty impressive.
A TikTok video has gone viral for uncovering just how your favorite bit of retro kit actually works.
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The account Macrofying pretty much does what it says on the tin - it zooms into objects, showing you details of how they work up close.
A CD has been put under the microscope - and while it looks cool, what does it actually mean?
Luckily, TikTok account Elysium Glimpse has reposted the video with a bit more background.
CDs work by "encoding small pits and lands (0s, 1s) onto the surface of the CD", the TikTok account explains in a post that's clocked up 792.K thousand likes and a whole lot of conversation.
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"This binary code is then interpreted by highly precise lasers, enabling the player to accurately reproduce the sound."
And those lasers that are doing all the hard work interpreting the code?
According to the video, they're a mind-blowing one-sixth the diameter of a human hair.
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As you can probably imagine, people are pretty gobsmacked in the comments.
"I don't understand how humans figured out how to do this like whatttt," one TIkToker said in a comment that's racked up 39.7K likes.
"I WAS JUST WONDERING TODAY HOW A CD WORKS," another exclaimed.
While the intel is making some feel rather inferior: "Ok at this point I know nothing about anything."
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Considering CDs are considered outdated tech, perhaps we don't actually want to know how something like a smartphone actually works - we're just not sure we could wrap our tiny little minds around it.
But who knows - maybe CDs will have a renaissance sometime soon, just like records.
So if you were tempted to chuck out your discs, maybe keep them for now in case they become cool again.