uploading a game to another pc

As i said in my last question, my game is almost finished, Yaay ^.^ I asked before, if it was possible to just put my already built game in a pendrive and upload it to another pc, then just play it, and they answered me that i could, but i didn’t understand everything. Do i need to make a setup installation for my game? Is it really required? Or i can LITERALLY use a pendrive like a crazy and distribute my game around and everyone could play it just by opening it’s folder? And, if a setup is not necessary, why all unity games have a setup??

Assuming you’re talking about Windows… you just need the .exe file and the Data folder of the same name which are created when you hit build.