Why are DB depicted as circles of stacks?

[Tom is a Door]

What is this thing? often represents databases? I would assume Database servers are rectangle boxes stacked.

[Origami Cactus]

I would guess HDD disks: (harddrives hold data)

[Origami Cactus]

Here is a better look at an ancient giant multi disk HDD:

Spoiler

 

[Uttamattamakin]

4 hours ago, comander said:

"why does save look like a floppy disk? What's a floppy disk?"

That's a good question.... why in 2019 does the "save" button often look like a 3.5 inch floppy?  Wouldn't making it look like a USB key or even a cloud make more sense? *

 

Even if you consider old hands who grew up with those, or were used to those from the mid 1980's to early 00's   It's been 15 years since those have been relevant!    

Maybe it's like asking why any ideogram ever looks the way it does.   

*These days saving and a database would likely have the same icon... a cloud. 

[Bitter]

"why do you say hang up the phone?" - my friends children to my friend.

 

Yeah, lots of outdated iconography and phrases. Rewind anything, rolling a window up or down, dialing a phone, etc.

[NineEyeRon]

54 minutes ago, Uttamattamakin said:

even a cloud make more sense? *

This is happening, but usually to differentiate local and cloud saving.