Single Inline Memory Module
From Computer History Wiki
A Single Inline Memory Module (usually abbreviated to SIMM) was a standard main memory technology from the early Pentium era. They consisted of memory chips mounted on a small standard-format printed circuit board daughter-board which would snap in place in a socket on the machine's motherboard.
These were far easier to install, remove and upgrade than the old sets of DIP memory chips. SIMMs were typically denominated by how many pins they had, with the common types being 30-pin and 72-pin SIMMs.
