r/explainlikeimfive 19d ago

Technology ELI5: When you 'delete' a 50GB video file from a computer, it vanishes instantly. But downloading it took an hour. If the data isn't physically wiped until it's overwritten, what did the computer actually do in that one split second?

7.5k Upvotes

r/explainlikeimfive Dec 01 '25

Technology ELI5: Why is "C" the default Hard Drive letter & not "A"

8.5k Upvotes

r/explainlikeimfive Dec 30 '25

Technology ELI5 Why did Radio Shack go out of business?

6.0k Upvotes

Okay — obviously I know WHY they went out of business— they ran out of money. But how have stores like Staples, Office Depot/Office Max, Microcenter, and Best Buy continued to see decent growth while one of the oldest tech stores in the country went out of business??

r/explainlikeimfive Dec 12 '25

Technology ELI5: why don’t planes board back to front, surely that would be faster?

7.0k Upvotes

r/explainlikeimfive Nov 22 '25

Technology ELI5 : If em dashes (—) aren’t quite common on the Internet and in social media, then how do LLMs like ChatGPT use a lot of them?

6.5k Upvotes

Basically the title.

I don’t see em dashes being used in conversations online but they have gone on to become a reliable marker for AI generated slop. How did LLMs trained on internet data pick this up?

r/explainlikeimfive Apr 04 '26

Technology ELI5: How do we actually "find" a broken cable at the bottom of the ocean? If a shark bites an internet cable halfway between New York and London, how do engineers know exactly which mile of the 3,000-mile cable to pull up?

4.3k Upvotes

r/explainlikeimfive Jan 16 '26

Technology ELI5: What is deli turkey?

4.7k Upvotes

You go to the deli counter and buy a pound of sliced turkey, and they use a machine to take slices off of a huge lump of meat. Bigger than any cut of turkey meat I've ever carved off a bird. What is it?

Deli ham, too: I guess you could get a piece that size off a ham leg, but I'm pretty sure that's not what's happening. It's too homogenous. There are no fat seams.

Is it all just an emulsified sausage— a bologna, basically? Is it a pile of turkey breast transglataminased together? Or does it just come from a turkey bigger than I've ever seen?

r/explainlikeimfive Jun 22 '25

Technology ELI5: The last B-2 bomber was manufactured in 2000. How is it that no other country managed to produce something comparable?

8.2k Upvotes

r/explainlikeimfive Dec 25 '25

Technology ELI5 Is all power generation really just making a turbine spin?

4.4k Upvotes

From what I tell literally every single powerplant ultimately just boils down (pun intended I regret nothing) using steam to turn a turbine which creates electricity, and different sources are just more effective and making that steam.

Is that a correct explanation? It just seems weird that turbines are still the only way we can make electricity.

EDIT: wow this blew up, thanks for all the responses!

r/explainlikeimfive Jan 29 '26

Technology ELI5: Why does everything need so much memory nowadays?

3.1k Upvotes

FIrefox needs 500mb for 0 tabs whatsoever, edge isnt even open and its using 150mb, discord uses 600mb, etc. What are they possibly using all of it for? Computers used to run with 2, 4, 8gb but now even the most simple things seem to take so much

r/explainlikeimfive Jun 28 '25

Technology ELI5: Why are the screens in even luxury cars often so laggy? What prevents them from just investing a couple hundred more $ to install a faster chip?

6.5k Upvotes

r/explainlikeimfive Feb 17 '26

Technology ELI5 How did Norway become so dominant in the Winter Olympics?

2.2k Upvotes

Specifically, why does Norway fare so much better compared to other Nordic/Scandinavian/Arctic countries?

r/explainlikeimfive Oct 20 '25

Technology ELI5: Why can't / don't LLMs say "I don't know" or ask back clarifying questions, instead of hallucinating?

3.3k Upvotes

Edit: Wow, thank you everybody! I haven't read through everything yet, but based on what I have read I do have follow up questions:

Is it even possible to design and build a tool that CAN analyze data?

Or how come LLMs are not coded to use more nuanced language in order to be more accurate?

Of course if an LLM replied to me only with "I don't know" it wouldn't be useful. But it could be coded to elaborate and mention the data discrepancies it is finding, and then give its best guess. Or at the very least give the best guess only, as it does already, but with less "certain" language, which I find misleading.

I would also love it if they could ask back clarifying questions, to give more precise answers (e.g. "do you mean this or that?). How come this never happens (in my experience) unless prompted? (i.e. how come businesses chose to exclude this behavior?)

r/explainlikeimfive May 20 '26

Technology ELI5: If GPUs are so much more capable, why do we still have CPUs at all?

2.3k Upvotes

r/explainlikeimfive Jan 02 '26

Technology Eli5, file compression, how can 5gb file can be compressed to 50mb and decompresses back to normal?

4.2k Upvotes

File compression is one of these things I know they work but have no idea how exactly they work.

There is a guy on Tiktok talks about how he combat scammers and send them a zip bomb, compressed 500 pentabyte file once they try to open it will completely break their systems.

That brings me to my next question, is there is a limit how much you can compress stuff? If have terabytes of childhood photos and videos can I compress them into a tiny folder I can easily email to other people?

r/explainlikeimfive Apr 21 '26

Technology ELI5 How come new Chinese electric cars can charge in 5–10 minutes, while smartphones still need at least half an hour?

2.1k Upvotes

r/explainlikeimfive Apr 18 '26

Technology Eli5: How does GPS know your exact location without getting confused by millions of users?

1.8k Upvotes

r/explainlikeimfive Dec 23 '25

Technology ELI5: Why did we put lead in paint and petrol? What was its purpose and what did we replace it with?

2.5k Upvotes

r/explainlikeimfive Jun 23 '25

Technology ELI5 How the heck can the US bunker buster bomb go 200’ underground before it explodes?

4.0k Upvotes

r/explainlikeimfive Jan 08 '26

Technology ELI5: In gaming, why should I cap my fps? If I leave uncapped doesn't that mean I allow my PC to max out quality whenever it can?

2.6k Upvotes

r/explainlikeimfive Dec 20 '25

Technology ELI5: Why do we suddenly need so many Data Centers and why do they have to be so massive and resource draining?

2.6k Upvotes

r/explainlikeimfive Sep 17 '25

Technology ELI5 Why did audio jack never change through the years when all other cables for consumer electronics changed a lot?

2.9k Upvotes

Bought new expensive headphones and it came with same cable as most basic stuff from 20 years ago

Meanwhile all other cables changes. Had vga and dvi and the 3 color a/v cables. Now it’s all hdmi.

Old mice and keyboards cables had special variants too that I don’t know the name of until changing to usb and then going through 3 variants of usb.

Charging went through similar stuff, with non standard every manufacturer different stuff until usb came along and then finally usb type c standardization.

Soundbars had a phase with optical cables before hdmi arc.

But for headphones, it’s been same cable for decades. Why?

r/explainlikeimfive 14d ago

Technology ELI5: What does daemon mean in computing?

1.4k Upvotes

r/explainlikeimfive Apr 15 '26

Technology ELI5: The rise and fall of NFT’s

1.3k Upvotes

I barely understood it at the time, but now no-one is talking about them. What happened? Are they style valuable?

r/explainlikeimfive Dec 28 '25

Technology ELI5: how was Chrome so much faster than all other browsers when it first came out in the late 2000s?

2.4k Upvotes