A DIMM is a type of memory module used in computers. It is a printed circuit board with one or both sides holding DRAM chips and pins. The vast majority of DIMMs are manufactured in compliance with JE
Two types of DIMMs: a 168-pin SDRAM module (top) and a 184-pin DDR SDRAM module (bottom). The SDRAM module has two notches (rectangular cuts or incisions) on the bottom edge, while the DDR1 SDRAM module has one. Also, each module has eight RAM chips, but the lower one has an unoccupied space for the ninth chip; this space is occupied in ECC DIMMs.