e.g. usually sold to suppliers of PC systems software comes without all the flashy trapping the retail pack comes with. This way the likes of Tiny/time offer 25 sets of software where all you get is the disc and small amount of paperwork.
For hardware usually means you get the item, brown box, software disc and little else as it is assumed you know how to install component.
Yes OEM usually lot cheaper than retail versions, lets face iot most of bin all the fancy trapping bits anyway and most manuals are on-line or via disc these days rather than in book form.