SDRAM
full spelling ： Synchronous Dynamic Random Access Memory
Synchronous Dynamic Random Access Memory (SDRAM) is a type of DRAM that can run at much higher clock speeds than conventional DRAM. SDRAM has a synchronous interface unlike the other dynamic random access memories which have an asynchronous interface.
SDRAM called Synchronous because SDRAM synchronizes itself with the CPU's bus speed. SDRAM chips are rated according to their maximum clock rate and their read cycle time.
SDRAM is a very popular memory technology in the electronics industry and had replaced virtually all other types of DRAM in modern computers, because of its greater speed, and much lower latency.
SDRAM are manufactured to compliance with standards established by JEDEC (Joint Electron Device Engineering Council), an electronics industry association that adopts open standards to facilitate interoperability of electronic components. Some of the largest manufactures of SDRAM are Samsung Electronics, Qimonda, Hynix and Micron Technology.