Difference between RAM and ROM

Parameter	RAM	ROM
Acronym for	Random Access Memory	Read Only Memory
Definition	It is the class of Computer data storage which takes roughly same amount of time to read or write data items regardless of the order in which data items are accessed.	It is the class of Computer data storage in which stored data can only be modified slowly, with difficulty or not at all.
Power Requirements	It can retain data if and only if power supply is on. Data gets lost on power failure. Hence data is stored temporarily.	It can retain data even if power supply is off. Data is stored permanently.
Types	SRAM (Static RAM), DRAM (Dynamic RAM).	Mask ROM, PROM (Programmable ROM), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM)