When countries import and export goods without restrictions is called?

I think that is called(most Favored Nation)is a term used by the US.most Nations are considered "Most Favored Nation"in fact,only a few nations are not on the Most favored Nation.Easy Trade Relations might be known as Free Trade or Open Markets,Tariff free zone,or Duty Free.these are the thoughts that come to mind just now.i hope this was helpful.