Memory with the achievement of direct, static, is less than the DRAM used, and often in places that the speed is too high, it is necessary to work the process. SRAM the ability to save the data, can be tens of meters high, Dara. without the need to refresh ( Refresh ). Ram, SRAM more quickly than DRAM, have and price also. SRAM and DRAM if your energy lose, all the contents stored on them will be lost.