This message was posted on behalf of Intel Corporation
Tray processors are found in pre-build systems that are integrated by OEMs, meaning that these prices are for those manufactures (OEMs) and the ones that only have TRAY price would be only available in pre-build systems.
A boxed processor is the one you can purchase to place inside your new rig (computer), these can be puchased by end users.
TRAY: used in OEM systems
Box: used by end users
This article could also assist you on this matter: http://www.intel.com/content/www/us/en/support/processors/000005721.html
If you require any further information or support, do not hesitate to contact us back.