Justice is when each person or group is given what is due them based on their intentions, efforts, or effects on the world. When one does good in the world, goodness returns to the doer. When one does harm, the harm returns also to the one who caused it. The fruits of creativity and industry are harvested proportionally by the persons who brought them into being.
Though perfect justice is impossible, we embody the virtue of justice when we seek to treat every individual with fairness and equality. Since we all are prone to bias and prejudice, we can approximate justice only by rigorously safeguarding against these. Because we value justice so deeply, every human community puts into place rules and processes that attempt to ensure justice or equity among members.