-Memory comes in two flavors to worry about on PC system. Most of the memory you will work with is just a module that plugs into the motherboard. First off we need to look at SIMM's.
-SIMM (Single Inline Memory Module), this is an older standard that is still around. Most of SIMM's come in 30 and 72 pin format meaning as much as 72 pins on the memory module. The shorter 30 pin module (4MB RAM per Module) is found in older computer such as an 386 or a older 486. The 72 pin (Up to 32 MB RAM per Module) was used for newer Pentium class machines and was a leap in technology for the PC. Something to take note of in a SIMM is that it needs to be installed in pairs on the motherboard in order to fill up one bank. The reason for banking the SIMM's in a Pentium scheme is what's called interleaving. This amounts to even bits being stored in one bank and odds in the other. This helps out in performance with the Pentium system. If unsure about your machine look at the motherboard manual or contact the manufacturer of the system.
-DIMM (Dual Inline Memory Module), this is a newer module that allows for only one module to fill up a bank. These modules also put the memory chips on both sides of the module and can fit up to 64 MB on a 168 pin connection. That's BIG! Most manufacturers will tend to move to just DIMM and leave the SIMM in the dust. Most newer systems will utilize the DIMM slot with SDRAM modules.
