What Is (or Was) Affirmative Action?

In June of 2023 the Supreme Court determined that affirmative action -- a practice that had been common in some colleges and universities since the 1960s -- was a violation of the Equal Protections clause of the 14th Amendment. So what, exactly, are these schools not allowed to do anymore? What does it have to do with race and diversity? How was it supposed to work... and did it?

https://podcasts.apple.com/us/podcast/what-is-or-was-affirmative-action/id1195657423?i=1000624497193