Is USC the University of Southern California or University of South Carolina?

It can refer to both, but it'll usually be University of Southern California as it is more popular/prestigious. However UofSC only refers to University of South Carolina.

So if you ask someone in the Carolinas they are gonna say South Carolina and someone in SoCal will say it’s Univ S Cal. But a random person will say it’s the California one. Typically South Carolina’s acronym is UofSC. Of course if you ask a UofSC grad who’s in SoCal they would likely say thier Alma Mater. But that’s my very educated guess. In fact UofSC typically calls themselves UofSC.

Hope this helps and feel free to comment if you’s like clarification as I’d be more than happy to help!