EPROM
Short for Eras able Programmable Read-Only Memory, ERPOM is a memory chip that was invented by Dov Frohman that can be read from but not stored to. However, if exposed to ultraviolet light and can be reprogrammed if needed. Hardware manufactures use EPROM when it may be needed that the data contained on the EPROM needs to be changed. An EPROM chip is easily distinguishable by a small glass circle that exposes the chip that can be reprogrammed.
Also see: EEPROM, Firmware, Memory definitions, PROM, ROM