Read-only memory storage memory storage has been recorded. not like main memory (RAM), store retains its contents even once the pc is turned off. a store is brought up as being nonvolatilisable, whereas RAM is volatile

• Data are stored in Memory after Power Off.
• System configuration(Processor /Mouse/Key Board) and date & time store 

What are the uses of RAM and store in an exceeding computer?
Read-only memory, or ROM, may be a kind of information stored in computers and alternative electronic devices which will not be simply altered or reprogrammed. RAM is brought up as volatile memory and is lost once the ability is turned off whereas store in non-volatile and therefore the contents are preserved even once the ability is changed.
What is the aim of a store in a ROM computer?
ROM may be a special reasonably memory that stores the directions that the pc uses once it ‘boots up’ – the BIOS (basic input output system). … the store may be a sort of memory that retains its information even while not power, therefore even once the pc is changed, it’ll not lose the info that is saved it.

Type of  ROM.
1.  PROMProgrammable read-only storage (PROM), or one-time programmable store (OTP), may be written to or programmed via a special device known as a promenade computer programmer.

2. EPROM.Erasable programmable read-only storage (EPROM) may be erased by exposure to robust UV (typically for ten minutes or longer), then rewritten with a method that once more desires more than the usual voltage applied. perennial exposure to ultraviolet {light|ultraviolet illumination|UV|actinic radiation|actinic ray} light can eventually wear out associate degree EPROM, however, the endurance of most EPROM chips exceeds a thousand cycles of erasing and reprogramming.

3. EAROMElectrically alterable read-only storage (EAROM) may be a sort of EEPROM which will be changed one bit at a time. Writing may be a terribly slow method and once more desires higher voltage (usually around twelve V) that is employed for scan access
4. EEPROM: Electrically effaceable programmable read-only storage (EEPROM) relies on the same semiconductor structure to EPROM, however, permits its entire contents (or selected banks) to be electrically erased, then rewritten electrically, so they have not been far from the pc
Flash memory.with a metallic element battery.

5.Flash memory is a contemporary sort of EEPROM fancied in 1984. non-volatile storage may be erased and rewritten quicker than standard EEPROM, and newer styles feature terribly high endurance (exceeding one,000,000 cycles

 CMOS Battery   RTC(Real Time Clock) & ROM’s RAM data is maintained.