Fincal Cut Studio Universal Binary Question....

hello all. just was confused on which final cut studio should i be downloading first on my MBP. i have two versions of final cut studio, one is not the universal binary, and the other is the older version, regular final cut studio. my friend said i needed to install the first final cut studio, non UB, before i install the universal binary version. is this true? also, what is this universal binary version? i don't quite understand it. i tried looking around for the answers, but i was just confused. thanks in advance.