SSD (Solid State Drive) storage media are used as an alternative to hard drive media, especially in portable computers. They offer different ways to store data than conventional hard drives. Instead of read heads and rotating platters, SSDs use NAND flash memory. Like conventional hard drives, SSDs do not lose any data during power failure. There are also other types of solid state memory, eg. SDRAM and DRAM. However, they do not extend as far as those using flash memory.