The chapter considers discrimination as one party being treated differently from another for unsound reasons. Focusing especially on business ethics, it shows how abstract questions about that general conception become practical and sometimes controversial issues. One is where the party treated differently is a group: difficult questions arise if the group is not institutionalized, as with some indigenous groups. Another issue is what sorts of different treatment amount to discrimination. If someone acts in accordance with accepted cultural norms, should we label the action as discrimination, where the cultural system disadvantages some people relative to others? This question is related to the role of culture in identity, and to other questions about the significance of people’s understanding and intentions. Ideas of “structural discrimination” raise the question whether it is appropriate to deal with such cases under the rubric of discrimination. Another general sort of question is what sound reasons there are for treating some people differently than others. Examples include whether work arrangements should be changed to overcome some people’s lack of ability, and whether people’s category membership may justify inference about lack of ability. The discussion considers various ways in which these and other questions are interlinked. A general suggestion is to restrict the use of the term “discrimination” to where it is most useful, and elsewhere to focus on rectifying disadvantage and managing diversity without destructive conflict.