Do you know which fork is for your salad and which one is for dessert? Then you have some refinement — good manners and taste.
Things that go through a process of refinement have been refined; they've lost their rough edges. For people, this means they have good manners, and for substances like oil and sugar, it means that their impurities have been removed. With refinement, things and people become more acceptable: the sugar's refinement makes it appropriate to serve at a fancy party, and your refinement makes you a perfect guest there.