Forgive my ignorance, what exactly is the difference between the Tristar C-100 and the CZ75 Compact?... Is this a clone or something?
Basically yes, AFAIK it is largely a clone, although IIRC there are a few minor differences. It's close enough that it supposedly takes CZ 75 Compact mags. According to what I've read online, the C-100 is more directly copied from the EAA Witness / Tanfoglio line than from the CZ.
FWIW Tristar is an importer. The pistol is made by Canik 55 in Turkey; the number 55 is part of the company name, NOT a model number, so the full name of the gun is the Canik 55 C-100. This pistol has bounced around between several different importers in the last few years, but AFAIK the pistol itself is the same.