Thanks! The difference between virtue and morality is that morality is acting based on the manners, as you say, of a society, doing the socially acceptable according to manners or customs, the traditionally correct. While the virtues are those qualities that refer to what is universally correct. Someone of a specific religion may be immoral in some place where their religion is not practiced, yet be virtuous at last.

People who don't believe in good and justice, and other similar ideas, tend to confuse it with morality and also believe that they are relative or subjective.

In case you are interested, here I leave a link for a post that I did talking about whether the good, the justice, etc. are relative or not.