# Why do I "install" an OS on my laptop but "flash" a ROM on my phone? **URL:** \ **Category:** Factual Questions\ **Created:** [April 7, 2015, 5:38pm UTC](https://boards.straightdope.com/t/why-do-i-install-an-os-on-my-laptop-but-flash-a-rom-on-my-phone/717048 "2015-04-07T17:38:15Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [April 8, 2015, 6:52am UTC](https://boards.straightdope.com/t/why-do-i-install-an-os-on-my-laptop-but-flash-a-rom-on-my-phone/717048/21 "2015-04-08T06:52:47Z")
> [@LSLGuy](#): > > And the engineering term for that \*clear all & rewrite \*process is “flash”… No. It was originally the next type of EEPROM… released in 1984… Whereas EPROMs had to be completely erased before being rewritten, NAND type flash memory may be written and read in blocks (or pages) which are generally much smaller than the entire device. NOR type flash allows a single machine word (byte) to be written—​to an erased location—​or read independently. Well anyway the term FLASH applies to the silicon chips permanent storage, while the OS in your computer goes on a hard drive. You can now of course have SSD which means chips emulate the hard drive, but its a special case… anyway the SSD appears as a file system,block, IO device to the CPU, while flash appears as a huge range of memory addresses to the CPU … (don’t get distracted by small memory buffers or the ability of the hard drive system to DMA … they are block techniques. ) ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [April 8, 2015, 7:09am UTC](https://boards.straightdope.com/t/why-do-i-install-an-os-on-my-laptop-but-flash-a-rom-on-my-phone/717048/22 "2015-04-08T07:09:30Z")
> [@Senegoid](#): > > And after that, the real fun started! Surprise, surprise! We discovered, the hard way, that the 4.3 restore program couldn’t restore from a 4.2 back-up. ☹ You know I felt a physical pain on reading that. I thought I had blotted it out of my memory. But no. The 4.2 to 4.3 jump was not a happy time. :mad: ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [April 8, 2015, 7:14am UTC](https://boards.straightdope.com/t/why-do-i-install-an-os-on-my-laptop-but-flash-a-rom-on-my-phone/717048/23 "2015-04-08T07:14:29Z")
> [@Rhythmdvl](#): > > Because your phone runs apps but your computer runs software. I believe that was a joke… a “correlation is causation” joke. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [April 8, 2015, 2:47pm UTC](https://boards.straightdope.com/t/why-do-i-install-an-os-on-my-laptop-but-flash-a-rom-on-my-phone/717048/24 "2015-04-08T14:47:48Z")
FTR, yes that was a whoosh. I had “,duh” tacked on to the end with a rolleyes, but on preview it looked a bit too snarky. ---
**Author:** ![DrCube](https://avatars.discourse-cdn.com/v4/letter/d/a3d4f5/32.png) [@DrCube](https://boards.straightdope.com/u/DrCube)\ **Post date:** [April 8, 2015, 5:05pm UTC](https://boards.straightdope.com/t/why-do-i-install-an-os-on-my-laptop-but-flash-a-rom-on-my-phone/717048/25 "2015-04-08T17:05:17Z")
> [@PatriotGrrrl](#): > > Someone in this very thread said that apps come from a curated app store. I’ve got programs on my phone that didn’t, including some that I’m pretty sure Google does not approve of, and some that I wrote myself. Yeah, but you already know that apps are just software. Someone who doesn’t know that probably doesn’t have a single app on their phone that wasn’t approved by Google, Apple or Microsoft. That’s why they think there’s a fundamental difference; the experience of discovering and installing apps on a locked down mobile device is very different from PC software. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [April 9, 2015, 10:32am UTC](https://boards.straightdope.com/t/why-do-i-install-an-os-on-my-laptop-but-flash-a-rom-on-my-phone/717048/26 "2015-04-09T10:32:09Z")
I don’t think anyone uses EPROM anymore. It’s all a type of EEPROM called Flash memory, and is the same stuff that is used in SSDs or USB thumbsticks. A phone has a regular OS on it’s partition, just like a computer does. If it didn’t, the user wouldn’t be able to flash their own devices. While part of it is due to history and how EPROMS were programmed, there still is usually a distinction in practice. Firmware is finely tailored to the exact device on which it is flashed. An installation, on the other hand, has to be configured to fit the device–even if the configuration happens automatically. I’m not sure this distinction exists on iDevices, though. They may be direct copies, or Apple may actually be installing the new iOS update. ---
**Author:** ![Digital\_is\_the\_new\_Analog](https://avatars.discourse-cdn.com/v4/letter/d/a88e4f/32.png) [@Digital\_is\_the\_new\_Analog](https://boards.straightdope.com/u/Digital_is_the_new_Analog)\ **Post date:** [April 10, 2015, 12:48am UTC](https://boards.straightdope.com/t/why-do-i-install-an-os-on-my-laptop-but-flash-a-rom-on-my-phone/717048/27 "2015-04-10T00:48:59Z")
EEPROMs are still used…just not as visibly to the general public. For instance, my ethernet IC allows for an EEPROM to set default behavior. [Previous page](https://boards.straightdope.com/t/why-do-i-install-an-os-on-my-laptop-but-flash-a-rom-on-my-phone/717048.md?page=1)