2015-02-11, 23:31
Not sure if this really belongs in tutorials... as it's more of an explanatory post. But I was replying to somebody else's question and realized that it would probably benefit more than just that poster to explain the basic differences between RAM and ROM so I decided to create a separate thread for it.
RAM is different from ROM. RAM stands for "Random Access Memory", and it is the memory that your phone uses when it's executing applications... Applications reside in the RAM while they are running, and then when you shut them down it clears out the RAM. This is always soldered on to the board. RAM is what's called "volatile memory" - which means that when the device is turned off, it gets cleared out. You don't permanently store files or applications in RAM.
What is currently called the "ROM" memory in a phone is a bit of a misnomer. ROM stands for "read only memory", and in the past it was a form of memory that could be written to once (usually using some form of specialized hardware/software combination), or at any rate was not easily changed by the end user. Think of the BIOS on your computer. Nowadays, the term ROM is more generally used for the file system that is built into the phone itself, where the operating system files are stored (not user-changeable unless you root), but also where regular user files and applications/application data are stored as well. You'll often see phones described as "1gb RAM/8gb ROM", for example. The "ROM" in this description is referring to the non-volatile memory (ie, the memory that doesn't get wiped when the phone is turned off) in the phone. It is generally expected that the "ROM" storage on a phone will be soldered onto the board (as this is generally faster), but in some cheaper/shadier phones the manufacturers have cut corners to save money, and instead simply put a micro-SD card inside the phone and set up the operating system/user file area on there instead. It's not necessarily a BAD thing, but it's definitely preferable to have your ROM storage as a chip instead of an SD card. It's more reliable (generally speaking) and better performance.
AND, to make things even *more* confusing, the term "ROM" is now also used in the modding/development community to describe a flashable OS build for a given phone. For example, CyanogenMod is often described as a "custom ROM".
Hope I've been able to clear things up for some folks! Feel free to correct me if I've made any mistakes as well, I'm writing this off the cuff on not that much sleep.
RAM is different from ROM. RAM stands for "Random Access Memory", and it is the memory that your phone uses when it's executing applications... Applications reside in the RAM while they are running, and then when you shut them down it clears out the RAM. This is always soldered on to the board. RAM is what's called "volatile memory" - which means that when the device is turned off, it gets cleared out. You don't permanently store files or applications in RAM.
What is currently called the "ROM" memory in a phone is a bit of a misnomer. ROM stands for "read only memory", and in the past it was a form of memory that could be written to once (usually using some form of specialized hardware/software combination), or at any rate was not easily changed by the end user. Think of the BIOS on your computer. Nowadays, the term ROM is more generally used for the file system that is built into the phone itself, where the operating system files are stored (not user-changeable unless you root), but also where regular user files and applications/application data are stored as well. You'll often see phones described as "1gb RAM/8gb ROM", for example. The "ROM" in this description is referring to the non-volatile memory (ie, the memory that doesn't get wiped when the phone is turned off) in the phone. It is generally expected that the "ROM" storage on a phone will be soldered onto the board (as this is generally faster), but in some cheaper/shadier phones the manufacturers have cut corners to save money, and instead simply put a micro-SD card inside the phone and set up the operating system/user file area on there instead. It's not necessarily a BAD thing, but it's definitely preferable to have your ROM storage as a chip instead of an SD card. It's more reliable (generally speaking) and better performance.
AND, to make things even *more* confusing, the term "ROM" is now also used in the modding/development community to describe a flashable OS build for a given phone. For example, CyanogenMod is often described as a "custom ROM".
Hope I've been able to clear things up for some folks! Feel free to correct me if I've made any mistakes as well, I'm writing this off the cuff on not that much sleep.