Flash memory is a form of EEPROM (Electrically Erasable Programmable Read-Only Memory) that allows multiple memory locations to be erased and/or written using electrical signals. It is a rewritable memory chip that, unlike a RAM(Random Access Memory) chip, power supply is not required to hold the contents. It is commonly used in memory cards, USB flash drives, MP3 players, digital cameras and mobile phones. Flash memory is also an example of a Non-Volatile Read Write Memory (NVRWM).