Electrically Erasable PROMs (EEPROM or E2PROM) are non-volatile memories, they are electrically erasable and rewritable. The erasure of the memory content is done with a voltage surge. Incomputers with the possibility of Flash BIOS, special BIOS ROMs are used, the EEPROMs.
EEPROMs are comparable to Flash memories, they are also called Flash EEPROMs, but in contrast to them they differ in the writing and reading process, which is done byte by byte in EEPROMs, and block by block in Flash memories. EEPROMs are characterized by short access times for reading and writing, but are slower than flash memories. A further development with the shortest access times is the Flash EEPROM( FEEPROM).