The Baron

Usually OEM means it only comes with the Hardware and Drivers. Retail will often come with extra software like little helper applications, DVD software, or games. I would check the list of features though to make sure that it isn't mising any hardware features though. Some versions of products are only available OEM and they may be a "downgraded" version of the product. One example of this is the ATI Radeon LE graphics card which has some of the better features of the card disabled and is only available OEM.