Tze-da-KAH is Hebrew for justice. It's most often translated as giving money to the poor or "charity". The difference is whereas charity has to do with kindness of heart, tzedakah is a commandment and we are obligated to do our part to make the world just no matter how we feel about it. Even the poorest of the poor is commanded to give tzedakah. The traditional amount, based on sources in the Torah, is 10% of our income.