An employment decision in some way harms or disadvantages an employee or a job applicant.
The decision is based on membership in a certain group, rather than on individual merit.
The decision rests on prejudice, false stereotypes, or the assumption that the group in question is in some way inferior and thus does not deserve equal treatment.
Forms of discrimination: Discrimination can be individual or institutional, intentional or unwitting.
Arguments against discrimination: It involves false assumptions about a group and harms its members, so utilitarians would reject it due to its ill effects on overall human welfare.
Kantians would repudiate it as failing to respect people as ends in themselves.
Discrimination is also unjust.