One of the human skills that can be learned and refined, enabling us to maintain serene relations with others and live well together in society. It’s the politeness of the heart, and it’s universal.(1)
Social politeness (etiquette, good manners)
A set of social codes to be respected, enabling those who practice them to recognize each other, and thus discriminating against those who don’t (e.g. table manners).
Since the etymology comes from the Latin word politus, meaning smooth, we could say that politeness is behavior smoothed by education in social customs and savoir-vivre.