RAM and ROM perform different functions in computing devices, but the traditional distinction between them no longer fully describes the technical reality. Random-access memory, or RAM, is the space where a device keeps the data and programs the processor is currently working on, while ROM was historically associated with storing the fixed instructions needed to start the device.
What does RAM do?
When you open a browser tab or run an application, data is moved from storage into RAM so the processor can access it very quickly. Most modern devices use a type of DRAM, which stores bits as electrical charges inside small capacitors that need to be refreshed thousands of times per second. When power is interrupted, this memory loses its contents.
RAM applications vary by device. Desktop computers use DDR5 modules, while phones and thin laptops generally rely on LPDDR soldered to the board, and graphics cards use GDDR chips around the graphics processor. Greater capacity allows more applications to run, more tabs to be opened, and reduces reliance on slower storage when memory fills up.
RAM’s importance is not limited to theoretical performance. The article indicates that traditional contract DRAM prices rose by between 90 and 95 percent quarter over quarter at the beginning of the year, according to TrendForce, with AI data centers taking up a large share of supplies. Micron also announced last year that it would end its consumer Crucial brand to focus on higher-margin demand from AI data centers, and operations stopped in February.
Why is ROM no longer “read-only”?
The earliest ROM chips had their data built into the circuitry itself, meaning that modifying them required manufacturing a new chip. PROM then appeared in 1956, designed by Wen Tsing Chow of American Bosch Arma so that the U.S. Air Force could load targeting data into missile-guidance computers by burning tiny fuses; writing to it was permanent.
In 1971, Intel engineer Dov Frohman developed erasable EPROM using ultraviolet light, and EEPROM later enabled electrical erasure. Fujio Masuoka of Toshiba subsequently led the development of flash memory, which appeared in NOR form in 1984 and then NAND in 1987. NAND is now found in SSDs, phones, memory cards, and USB drives.
What changes in practice?
The firmware chip on a motherboard is still sometimes called BIOS ROM, but it is actually a small flash chip that can be rewritten when firmware updates are installed. The same applies to the word ROM in the specifications of some phones, such as Xiaomi’s Redmi 13; it usually refers to UFS or eMMC flash storage, with system partitions restricted to read-only access, rather than to traditional ROM.
ROM that is physically manufactured so that it cannot be changed still exists, but it is concentrated in very inexpensive electronics and small controllers whose instructions are not expected to be modified. RAM has therefore retained its basic technical meaning, while ROM in modern usage has become a general label for memory that the user is not expected to modify, even when it is reprogrammable.