difference between RAM and ROM.?

·         What is the difference between RAM and ROM.?

RAM	ROM
1)      It stands for Random access memory.	It stands for read only memory.
2)      RAM is temporary type o memory.	ROM is a permanent memory.
3)      It can do both read and write operation.	It can do only Read operation.
4)      RAM lost it's contain, if its power is off.	RAM does not lose its contents if power is off.
5)      It is called volatile memory.	It is called non-volatile memory.
6)      It is expensive.	It is cheaper.
7)      It is of two types. a)      SRAM b)      DRAM	It is of three types. a)      PROM b)      EPROM c)       EEPROM