Some Definitions..

ROM - Read Only Memory. This is an unerasable, non-volatile data storage memory chip. It must be programed by the factory.

EEPROM - Electrically Erasable Programmable Read Only Memory. This is an erasable, non-volatile data storage memory chip. It is erased and reprogrammed while it is connected to external circuitry and is powered up. It can be programmed many times.

EPROM - Erasable Programmable Read Only Memory. This is an erasable, non-volatile data storage memory chip. It is usually erased by removing the memory chip from its circuit and exposing the window to intense ultra violet light. It can be programmed many times.

RAM - Random Access Memory. This is an erasable, volatile data storage memory chip. RAM is a generic name for all types of RAM.

DRAM - Dynamic Random Access Memory. This is an erasable, volatile data storage memory chip. Also see RAM and SRAM. The term dynamic means this RAM needs intervention from a controller to refresh what has been stored in it so it will not forget and it will forget everything if it looses power.

SRAM - Static Random Access Memory. This is an erasable, volatile data storage memory chip. Also see DRAM and RAM. The term static means this RAM does not need any intervention to remember what has been stored in it, but it will forget everything if it looses power.