Unix is a specification. Mac OS X is a certified implementation of Unix. This like asking "What is the difference between a turtle and a red-eared slider."
In reference to installation CDs or binaries, Universal refers to its ability to run on both PowerPC and Intel-based Macs. PowerPC binaries can only be run on Intel Macs via emulation, which can be...
OS X is the all encompassing term for every version of Apple's OS 10 software from 10.1 to 10.6 (as of July 2010). Basically, Mac OS X is 10.3 Panther, but is also 10.1, 10.2, and every other version...
Mac OS X looks different and costs less. Originally Microsoft licensed aspects of the Mac OS from Apple to allow them to create their Windows system. This resulted in long running dispute between the...