Difference Between ROM and RAM


Main Difference

For a computer system to work there is always the requirement of memory and critical files which are stored on the system. This can be done with the help of storage devices and options which can assist in reading the data on the storage devices. This can be done in two ways for digital devices in the form of ROM and RAM. They both are known as Read Only Memory and Random Access Memory respectively. Both have differences between them. The main one is that RAM stores memory for a short period of time and when the system is shut down the data is lost. ROM, on the other hand, stores data forever. There can be changes made in the data on the RAM, but no such changes can be done on the ROM data. This helps to make the observation that ROM data is only available in the read mode while RAM data can be read and written according to the requirements. RAM is available in two different types while ROM has 4 other forms, all of these are used in the system according to the specifications. There are many other smaller differences as well which will be discussed at the end.

Comparison Chart

Read Only MemoryRandom Access Memory
Reads dataWrites data
Helps to keep the main files of the application what were installedCan run different applications which are installed on the computer.
Cannot be madeCan be made

Definition of ROM

ROM has known as Read Only Memory, which is used in digital devices such as computers and cell phones. It is used to store memory on a proper basis which cannot be changed quickly and requires certain actions for the amendments to be made. All the applications and drivers are installed on the ROM because it can keep memory safe and for a longer time. Once the product is manufactured there can be no changes in the hardware of the system and the specifications it has because they are entirely stored in the ROM. Although this may have its benefits there are some drawbacks too for example if there are some errors which are making the process difficult or bugs which need to be debugged, they cannot be removed, and the problem persists. Because of this mostly the applications or program which do not require any modification are stored in RAM. Keeping all of this in retrospect, recently a different type of read only memory has been introduced which is available for modification and can be programmed to make some changes, but this experiment is in the initial stages.


Definition of RAM

RAM is known as Random Access Memory and is a different form of storing data than the ROM. The main advantage of this is that data can be used in a short time since it is available to be read at any instant of time. RAM keeps the location of data in memory and whenever the command it prompted it brings that memory for the user. In the past, devices such as hard disks and drum memories were used to perform this task and took considerably longer time for the system to work. It operates on the principle of multiplexing and de-multiplexing which help in reaching the line where the data is stored for reading and writing. It can divert the user to different locations and memories at the same time which is another advantage it has over the previous devices. The only disadvantage it has is that if the system is powered off or any other error takes place, the data which is written will be lost. Efforts are being made to reduce this problem but still a lot of work is to be done in that regard.

Differences in a Nutshell

  1. RAM is known as Random Access Memory while ROM has known as Read Only Memory.
  2. RAM allow the user to read and write data while ROM only allows the user to read data.
  3. RAM can run different applications which are installed on the computer while ROM helps to keep the main files of the application what were installed.
  4. ROM has all the critical files required to boot the system while RAM does not keep any such files.
  5. Data stored in the ROM is safe and cannot be altered with, data stored in the RAM can be lost the moment system is turned off.
  6. RAM memory can be accessed easily at any instant of time while ROM memory cannot be accessed all the time.
  7. Alterations can be made in the RAM, but no changes can be done effortlessly in the ROM.
  8. The main types of RAM include RAM and DRAM while the main types of ROM include PROM, EPROM, and EEPROM.


Computer architecture is something that is a mystery for people who are general users and do not have a detailed knowledge of it. The two terms ROM and RAM are similar ones which are considered same but are different in the working and functions. This article, therefore, gives a proper understanding of the two types for people to get a clearer idea.

Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss