It is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It is primarily used in memory cards, USB flash drives, MP3 players and solid-state drives for storage and transfer of data between computers and other digital products. It is a specific type of EEPROM which can be erased and programmed in large blocks. Flash memory costs far less than EEPROM and therefore has become the dominant technology. It stores information in an array of memory cells made from floating-gate transistors. It is suitable for use in mass-storage devices such as memory cards. The first removable media format was SmartMedia in 1995, and many others have followed, like Multimedia Card (MMC) and Secure Digital (SD). New card formats are coming like, miniSD and microSD and are small like, the microSD card is 1.5 cm2, with a thickness of less than 1 mm. microSD capacities range from 64 MB to 32 GB.