RAM and ROM are both types of Primary memory. RAM is volatile memory that requires power to retain information and loses everything when the power is cut. Whereas ROM is non-volatile memory that stores programs and instructions permanently. Both of these play a crucial role in computer systems. In this article, we are looking at their difference, advantages, and disadvantages in detail.
Difference Between RAM & ROM
| Basis | RAM | ROM |
|---|---|---|
| Full form | Random Access Memory. | Read Only Memory. |
| Nature | RAM is volatile. Its contents disappear when the power is switched off. | ROM is non-volatile. Its contents stay even when the power is off. |
| Purpose | It holds the programs and data the CPU is using right now, like a temporary workspace. | It holds permanent instructions the computer needs to start up, such as the BIOS or firmware. |
| Read and Write | The CPU can both read from and write to RAM quickly and as often as needed. | Data is normally only read. Writing is either not possible or needs a special process. |
| Speed | It is much faster, so the CPU does not have to wait for data. | It is slower than RAM. |
| Capacity | It is larger, usually 4 GB to 64 GB in modern computers. | It is much smaller, often only a few MB, because it stores only essential startup instructions. |
| Cost | It costs more per unit of storage. | It costs less per unit of storage. |
| Data Change | Data is constantly overwritten as you open and close programs. | Data is written once by the manufacturer and rarely changed. |
| Types | SRAM (static) and DRAM (dynamic). | PROM, EPROM, and EEPROM. |
| Example | The memory sticks plugged into a laptop or desktop motherboard. | The chip that stores the BIOS on a motherboard. |
What is RAM?
RAMstands for Random Access Memory. It is a volatile memory of a computer; it loses data when the device is turned off. RAM holds currently executing instructions and programs. DRAM and SRAM are types of RAM. DDR4 and DDR5 are examples of RAM.
What is ROM?
ROMstands for Read-Only Memory. It is a non-volatile type of memory; it stores data when the power supply is terminated. ROM is read-only memory that store firmware. Its types are PROM, EPROM, and EEPROM.
Frequently asked questions
Is ROM faster than RAM?
No, RAM is much faster than ROM. The CPU does its work in RAM, so it needs that speed, while ROM only has to hold fixed instructions.
Can RAM be used as ROM?
No, RAM loses its data when the power is off. It cannot hold permanent startup instructions, which is why computers need ROM.
Is phone storage RAM or ROM?
Phone storage is flash memory, which spec sheets usually call ROM. RAM is separate and holds the apps you have open right now.
Why does a computer need both RAM and ROM?
ROM holds the startup instructions that run when you switch the computer on. RAM then holds the operating system and the programs you are using.
Published October 2026. Last verified: October 2026.