Whats is the Difference between RAM and ROM

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Have you ever felt confused between RAM and ROM while dealing or talking about computer and mobile devices?

Well if yes, then let’s solve this for once and all!

What are RAM and ROM

RAM is an acronym of Random Access Memory whereas ROM stands for Read Only Memory, but let’s stop here and first understand what are these and why do we have these two types of memories rather than just cramming about the full forms.

These days RAM and ROM are not limited to Computers only as the mobile devices, tablets, printers, smart watches, smart home appliances, televisions etc that we use; all are comprised of microprocessors, RAM and ROM.

Both of these memories are used to store data in a computer and provide the user the access to the stored data when required, the usage of these memories or the situations they come into play differs in terms of the operation of the computer or other electronic devices. For example –

  • When we switch on the computer/device, during the bootup process it picks up the PREWRITTEN script/data from the ROM. Basically, it follows the set guidelines mentioned in the ROM to carry out a function (booting up of computer is one such functions, there are much more; like how should a computer print etc)
  • When the computer is running and you open an application (eg. MS Word, game, browser etc), RAM starts operating. The RAM further to this gets his set of instructions from the ROM and then RAM works in real time


Now let us do a side by side comparison of the two memory types:

It’s a read and write memory, instruction set changes as per the requirement Data is prerecorded, once written cannot be removed but can only be read (except for EPROM)
Its volatile means the data stored will be deleted when the computer goes to off state. Which means that the data stored is power supply dependent Its Nonvolatile means the data stored doesn’t delete even if the computer system is turned off. That means ROM storage is not power supply dependent
RAM is faster, Computers can read from RAM very quickly and also they can write new data in RAM faster ROM are comparatively slower, writing data to a ROM chip is a slow process (but done once, while manufacturing)
A RAM chip can store multiple gigabytes (GB) of data A ROM chip typically stores only several megabytes (MB) of data
RAM chips are bigger in size ROM chips are smaller in size


*Ping point: Both these memories have further types, which are explained below briefly:


  1. DRAM – Dynamic RAM; is a type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit. It needs to be periodically refreshed.

It uses a single transistor to store each bit, which causes a need to refresh for the charge to remain.

  1. Example: main memory in a computer like DDR3
  2. Size: 1GB to 6GB in smartphones and tablets; 4GB to 16GB in laptops
  1. SRAM – Static RAM; it uses a pair of transistors in a flip-flop or seesaw motion to maintain the charge. This eliminates the time-consuming need to refresh, which makes SRAM considerably faster but limits its density or capacity potential. SRAM does not have to be periodically refreshed.
    1. Example: L2 and L3 cache in a CPU
    2. Size: 1MB to 16MB


  1. PROM – Programmable read only memory; it’s a memory chip on which we can store a program, but once it’s used we cannot delete the data and use it to store something else. These are also nonvolatile.
  2. EPROM – Erasable programmable read only memory; it’s a special PROM which can be erased by exposing it to the ultraviolet light.
  • EEPROM – Electrically erasable programmable read only memory; it’s a special PROM which can be erased by exposing it to the electrical charge.

How it works

Ram_Rom_Computer system


The Computer system needs any type of storage/memory system to fetch and execute the data. Memory is used by the computer to perform few functions quickly. Suppose if the computer system has to go to the hard drive every time it needs some guidelines or information to perform some task; it will be dead slow, isn’t it. Therefore some information is kept in quick access memory, both permanent and temporary for the computer to work efficiently and quickly.

Now we will see with the help of a flow chart how these memories work in a computer system:



These days computers, mobile phones and other processor and RAM/ROM based devices are coming with faster processing power and bigger capacity RAMs and ROMs providing the consumer with amazing performance lightning speeds to carry out complex tasks, of course the prices of these devices varies in line with their performance capabilities.

We have seen a growth from; a RAM with a capacity of few MBs to few GBs. Let’s see what future have in store for us.


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One Comment

  1. tructuyencasino November 30, 2020 Reply

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