A definition for anyone who might need to read it.

Discrimination is the prejudicial treatment of an individual based on his or her membership - or perceived membership - in a certain group or category. It involves the group's initial reaction or interaction, influencing the individual's actual behavior towards the group or the group leader, restricting members of one group from opportunities that are available to a group, leading to the exclusion of the individual or entities based on logical or irrational decisionmaking.[1]

Discriminatory laws such as redlining exist in many countries. In some places, controversial attempts such as racial quotas have been used to redress negative effects of discrimination -- but have sometimes been called reverse discrimination themselves.