http://plato.stanford.edu/entries/affirmative-action/

“Affirmative action” means positive steps taken to increase the representation of women and minorities in areas of employment, education, and business from which they have been historically excluded. When those steps involve preferential selection—selection on the basis of race, gender, or ethnicity—affirmative action generates intense controversy.

The development, defense, and contestation of preferential affirmative action has proceeded along two paths. One has been legal and administrative as courts, legislatures, and executive departments of government have made and applied rules requiring affirmative action. The other has been the path of public debate, where the practice of preferential treatment has spawned a vast literature, pro and con. Often enough, the two paths have failed to make adequate contact, with the public quarrels not always very securely anchored in any existing legal basis or practice.