Difference Between RAM and ROM

Both RAM and ROM are the two major classifications of memory. The crucial difference between RAM and ROM is that RAM is a volatile memory thus stores data only till the time the power is switched on. While ROM is a non-volatile memory that retains data even when the power gets off.

Another major difference between the two is that RAM allows both read and write data operation. As against ROM allows read operation only.

Content: RAM Vs ROM

1. Comparison Chart
2. Definition
3. Key Differences
4. Conclusion

Comparison Chart

Basis for Comparison	RAM	ROM
Stands for	Random Access Memory	Read Only Memory
Memory type	Volatile	Non-volatile
Memory capacity	1 to 256 GB per chip	4 to 8 MB per chip
Operation type	Read and Write both.	Only Read.
Speed	Fast	Comparitively slow.
Storage type	Temporary	Permanent
Also referred as	Primary memory	Secondary memory
Presence of data according to power source	The stored data in RAM lost in case of power failure.	Data retained in ROM even if the power is turned off.
Accessibility to processor	Processor can directly access the data in RAM.	Processor cannot directly access the data in ROM.
Cost	High	Comparitively low
Types	SRAM and DRAM	PROM, EPROM and EEPROM

Definition of RAM

RAM is an abbreviation used for Random Access Memory. It allows read and write operation of data by the user. It is referred to as temporary memory because the data present in this memory last only till the time the power supply is on. As once the supply gets off then the data present in it gets automatically cleared and cannot be restored.

It stores program or data of any recent on-going operation inside the system. And thus this memory allows the processor to read and write the data.

SRAM and DRAM are its two major classifications. SRAM stands for static random access memory. While DRAM is dynamic random access memory.

Definition of ROM

ROM is an acronym used for Read-Only Memory. Here the name itself is indicating that only read operation can be performed on this memory. This means the data in ROM is stored at the time of designing the system and hence user does not hold the authority to change the data present in it. The data in this particular memory is stored on a permanent basis thus power failure neither modify nor delete the data or program stored in this particular memory location.

Basically bootstrap programs are stored by ROM that comes into action once the system gets turned on. And thus processor does not hold the ability to directly access this memory.

However, the data in ROM can be rewritten. But this is done only by the use of some specific methods. And according to these methods, ROM is majorly classified as PROM, EPROM and EEPROM. Programmable read-only memory is abbreviated as PROM, erasable programmable read-only memory is abbreviated as EPROM and electrically erasable programmable read-only memory is abbreviated as EEPROM.

Conclusion

So we can say that due to different functionality both RAM and ROM are used by a system for proper and efficient performance.