What Is ROM? What Is The Full Form Of ROM?

ROM full form

Do you want to know what ROM is and what ROM is in full form? Then you are at the right place. 

Every computer system consists of two different memory storage units. One is volatile (RAM), and the other one is non-volatile(ROM).

This post will learn everything about ROM, its full form, and its different types in brief. Let’s begin.

What is ROM & Its Full Form?

The full form of ROM is technical just similar to mouse full form. ROM stands for “Read-Only Memory.” ROM is a memory device of a storage medium of the computer system to store information permanently. Read Only Memory (ROM) is primary-non-volatile memory. It is the primary unit of the computer along with RAM (Random Access Memory) which is a temporary storage medium. 

Read-Only Memory is named Read Only because users can only read the stored data and programs on this and cannot make changes. This is a permanent storage area of the computer system. 

The ROM manufacturers fill all the important programs into this device unit. Once this is done, you cannot make any changes, rewrite or erase the information. However, now, there are some types of ROM on which users can modify data. 

ROM contains electronic fuses which can be programmed to make specific interconnection patterns. The binary information which is stored in ROM is fixed by the designer and embedded during manufacturing time.

Once the pattern is embedded in ROM, it stays as it is even when the computer is switched off. This non-volatile memory or storage unit holds every kind of information even when the system is shut off.

The data stored on PC, laptops, mobile phones, TV, AC, tablets, etc., are all examples of ROM. For instance, when you turn on the computer, the screen does not appear right in the moment. It takes some time to gather all the stored information from ROM and then display it to you. 

ROM is used as Firmware storage, a software program attached to hardware or is programmed on devices like hard drives, keyboards, video cards, etc., all of this is stored in the ROM flash of hardware devices. 

Types of ROM

Now that we know ROM’s full form and define it let’s move onto different ROM types.

Masked Read-Only Memory (MROM)

MROM is the oldest type of ROM; now, it has become outdated and is not used anywhere in the world. MROM consists of a hardware memory device on which the programs and instructions are stored when it is manufactured. This means that it cannot be modified, erased, or reprogrammed later.

The MROM chips are made with integrated chips. These chips send current through an input-output pathway which is determined by the location of fuses among other columns and rows on the chip. The current has to pass along a path which the fuse enables so it can return via output chosen by the manufacturer. 

This is the primary reason why modification andrewritingg is not possible on ROM.

Programmable Read Only Memory (PROM)

PROM is the empty version of ROM. These types of ROM are manufactured as a blank memory and can be programmed by the user after purchase. You need a special tool called a programmer to reprogram the PROM.

The current on these chips travels through a pathway. The programmer can pick a particular path for current by burning any unwanted fuse and sending high voltage. Users can add instructions and data on the chip as and when required. This is the reason why PROM is also known as user-programmed ROM.

In order to write a program or instructions of PROM, you will need a PROM burner or programmer. The princess of programming PROM chips is also known as burning the PROM. Once you program it as desired, you cannot modify the data later. This is a one-time programmable device.

Erasable and Programmable Read-Only Memory (EPROM)

EPROM is another type of ROM that can be programmed and reprogrammed again by erasing old data. The method of dealing with data on this chip is very different. It comes with a quartz window through which UV lights of a specific frequency pass for 40 minutes in order to erase data.

This retains the content of EPROM until it is exposed back to UV light. You will need a PROM burner or PROM programmed if you wish to reprogram this chip.

Electrically Erasable and Programmable Read-Only Memory (EEPROM)

Those types of ROM, which can be reprogrammed repeatedly multiple times, are known as EEPROM. This world is similar to flash Memory. It can be reprogrammed and erased electrically without using UV light. The access time of these chips is between 45 to 200 nanoseconds.

The data saved in this memory storage can be rewritten or erased one Byte at a time. Byte per Byte, the flash memory can be written and then again erased in blocks. All of this together makes EEPROM faster than EPROM.

EEPROM is used for storing small amounts of data in electronic systems and computer devices like circuit boards. 


FLASH ROM is an advanced version of EEPROM. It can store information and data in an array or arrangement of memory cells made of floating-gate transistors. 

The biggest advantage of using FLASH ROM is that you can write blocks or even delete them of upto 512 bytes at any particular time. Whereas in EEPROM, data can be deleted or written on upto 1 byte. This makes FLASH ROM faster than EEPROM.

You can reprogram a FLASH ROM without having to remove it from your computer system. It has a super-fast access time of about 45 to 90 nanoseconds. Also, it is highly durable and can bear high temperatures under intense pressure.

Final Words:

ROM, known as Read-Only Memory with its full form, is an electronic storage unit built in a pc or other devices during manufacturing. You can find ROM chips in computers and various other electronic products like car audios, game consoles, car radios, and VCRs; all use ROM to practice smooth functioning. These are different types of ROM, and all of them have unique features you may have read in this post.

We hope now you understand everything about what ROM is and its full form. Before you switch to the next post, do not forget to leave a comment down below. 


Hey There! I am A Makeup Artist turned into a Content writer. Intrigued by the world of digital marketing, I am currently working as an SEO Content Writer. Being a fashion enthusiast I enjoy writing blogs on Beauty, Fashion and Fitness Trends.

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