If you’ve ever bought any computer components, you might have come across the term “OEM”. Typically this identifies bare-bones products that are intended for system builders to build into their systems, and therefore these products usually lack the refinements that would be present in a consumer-orientated retail package.
So I reckon from a consumer perspective OEM really stands for “Optional Extras Missing”, which surely makes more sense than the confusing proper term “Original Equipment Manufacturer“.