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This terms are usually confused with memory rank which describes a logical/electrical organization of a memory module instead of a physical one.
Usually, single-sided modules are single-rank and double-sided modules are double-rank (or sometimes quad-rank), though this doesn't have to be always the case. It's technically possible to put 4 ranks in only one side of the module, but this wouldn't be cost effective, it's more easy for the manufacturer to use both sides when trying to add more ranks. In the other hand, it's also possible to dedicate both sides of the PCB to just one rank so in that case the RAM would be double-sided and single-rank.