DIMMs have 168, 184, or 240 pins on the edge connector of the board and can hold from 8MB to 2GB of RAM. Info from my A+ book.
168
184
240
168
Independently.
independently
2.66" 204-pin SO-DIMM contains DDR3 memory. The one notch on the module is offset from the center of the module.
168 pins are used on SDRAM DIMM. 184 pins are used on DDR DIMM. There are either 30 pins or 72 pins used on SIMM. 184 pins are used on RIMM.
686 pins
enough
dimm
A DIMM is a dual inline memory module and gets its name due to the fact that the pins on either side of the module operate independently. SIMMs are single inline memory modules whose pins operate together. DIMMs are larger than SIMMs and are what are commonly used in computers today.
DIMM. Two types of DIMMs: a 168-pin SDRAM module (top) and a 184-pin DDR SDRAM module (bottom). Note that the SDRAM module has two notches (rectangular cuts or incisions) on the bottom edge, while the DDR1 SDRAM module has only one.
10
240
A dimm