Reference vs OEM Design

[mb1shop]

Sorry, this is probably a n00b question, but I have been browsing the Hardware forum looking for good options for some graphics cards I can put in a 2-3 GPU rig and I have seen a lot of posts related to Reference vs OEM Design cards.

My question, is that from searching eBay and other sites, how can I tell just from the photo which type of card it is? Is it as simple that reference cards have fans out the back??

Thanks in advance.

[epixoip]

Look at the official product photo on amd.com or nvidia.com. If the card you want to buy doesn't look like that photo, then it's an OEM design card.