SDRAM	Synchronous dynamic random access memory delivers bursts of data at high speeds using a synchronous interface. Its is actually SDR SDRAM (single data rate SDRAM) but is usually used to referred to as just "SDRAM".
Semiconductor	An element, such as silicon, that is intermediate in electrical conductivity between conductors and insulators, through which conduction takes place by means of holes and electrons.
Serial Presence Detect (SPD)	An EEPROM on certain memory modules used to store and provide information to the system using the module.
SGRAM	Synchronous graphics RAM. A single port DRAM designed for graphics hardware that requires high-speed throughput such as 3-D rendering and full-motion video.
Shrink	A reduction in die (chip) size. A reduction in the size of the circuit design resulting in smaller die sizes that increases the number of possible die per wafer.
SIM	Single inline module. Same as SIP except with a connector edge instead of leads.
SIMM	Single inline memory module. A high-density DRAM package alternative consisting of several components connected to a single printed circuit board.
Single Banked	A memory module with only one bank or row. See Bank.
SIP	Single inline package. A component or module that has one row of leads along one side.
SLDRAM	Synchronous link dynamic random access memory. SLDRAM is a type of SDRAM that uses a multiplexed command bus allowing fewer pins to increase bandwidth and allow higher FSB speeds.
SODIMM	Small outline dual inline memory module. Smaller and thinner than standard DIMMs, SODIMMs are typically used in laptop computers.
SOJ	Small outline J-lead package. A rectangular package with leads sticking out of the side of the package. The leads are formed in a J-bend profile, bending underneath and towards the bottom of the package.
SORIMM™	Small outline Rambus inline memory module. SORIMMs have a smaller profile that standard RIMMs and are used in laptop computers and systems that have strict size requirements.
SPD	Serial presence detect.
Speed	The time it takes to put information into memory or get information out of memory. It is measured from the time that an address and proper control signals are given, until the information is stored or placed in the device's output(s). RAM speed is typically expressed in nanoseconds (lower is faster) for EDO and FPM, and in MHz (higher is faster) for SDR SDRAM, DDR, SDRAM, and RDRAM.
SRAM	See static random access memory.
Static Random Access Memory	An integrated circuit similar to a DRAM (dynamic random access memory) with the exception that the memory does not need to be refreshed. Unlike volatile memory (ie, DRAM), SRAM retains its contents even when the main current is turned off.
Synchronous Memory	Memory that has its signals synchronized with the system clock. SDRAM and DDR are examples of synchronous memory types.
TAG	TAG memory acts as an index for the information stored in L2 cache. It is usually composed of SRAM.
TSOP	Thin small outline package. It is thinner and slightly smaller than an SOJ, with gullwing-shaped leads. A thin, rectangular package with leads sticking out the sides of the package.
Unbuffered memory	This is where the chip set controller deals directly with the memory. There is nothing between the chip set and the memory chips on the module as they communicate.
VCM	See Virtual Channel Memory.
Virtual Channel Memory	A memory architecture that is a variant of SDRAM, that has not been seen widespread adaptation.
Virtual Memory	This is system memory that is simulated by the hard drive. When all the RAM is being used (for example if there are many programs open at the same time) the computer will swap data to the hard drive and back to give the impression that there is slightly more memory.
VRAM	Video RAM. DRAM with an on-board serial register/serial access memory designed for video applications.
Write time	Time expended from the moment data is entered for storage to the time it is actually stored in the memory cell.