Original Equipment Manufacturer (or Maker) applies to goods supplied direct for putting into new equipment. Some finds its way into retail at discount. Goods marked Retail usually have finer packing, better documents, clearer warranty info, etc. Sony, and perhaps others, refuse to condone OEM, and you may find bother with some on-line support for OEM serial nos. Generally OEM can be a good buy from a reputable supplier.
One big difference with Microsoft OEM products (and, I believe most other software manufacturers): your warranty or guarantee is with the OEM vendor, not Microsoft. In other words, if you buy an OEM edition of Windows XP from (say) eBuyer or Overclockers.co.uk and the disc is faulty, Microsoft WILL NOT exchange the disc for a good one. You have to go back to the vendor for a replacement. MS also don't provide software support for an OEM product, that's down to the OEM vendor too.
The rationale behind this is that when you purchase retail pack software you pay an extra (large!) sum of money for the after-sales service. OEM software doesn't carry the price premium, therefore you don't get the support!
So, as with most things in life, you pays your money and you makes your choice; £145 for a retail copy of Windows XP Home Edition with full MS after-sales service or £70 for an OEM edition with accompanying support 'risk'.
AMD 4 ever. Are you sure Sony OEM is not spin? I don't think you can buy a Sony DVD writer model DRU-510A as OEM, nor a DW-U10A as Retail. I guess it's market manipulation. The models are not identical.
This is yet another old chestnut question in these forums.
Many of the big online retailers such as dabs, Scan etc supply many components and hardware such as CD-ROM and DVD-ROM drives, soundcards, some graphics cards etc in OEM form.
The main benefit is that, berift of fancy packaging and, for example, games software for graphics cards, a considerable financial saving can be made.
Any drivers etc that are required (and Windows drivers are all that are needed for CD/DVD-ROM drivers and rewriters) can be downloaded from the manufacturers' websites; there is also the advantage that they will be the latest drivers.