a circuit board that contains all the RAM components on it, to serve as 1 unit, for example, as a 2GB unit.
So a computer that has 4 DIMMs, each with 2GB, will be 8GB of RAM.
And SIMM just means the slot contacting points are redundant on both sides, while DIMM are independent contacting points. And SO-DIMM is half the size of a DIMM.
Is there any case where a SIMM or DIMM is actually more than 1 circuit board? Or do they ALWAYS refer to 1 circuit board?