Flash memory is the high density device. It is a non volatile memory. It is fast in reading and writing data. This is because it writes data in Chunks or blocks. Flash memory is an electrically reprogrammable device. The contents from the flash memory are erased in blocks and not in bytes. The block size can range from 256 bytes to 16 kilobytes. Flash memory can replace hard disk in portable computers. Flash memory is primarily used in memory cards and USB flash drives for general storage and transport of data between computers and other digital products. Some of the latest Memory Cards include multimedia card, SD card, compact flash, memory stick etc.