What was the blacklist? what did political witch-hunts result in these lists?

The Hollywood blacklist—as the broader entertainment industry blacklist is generally known—was the practice of denying employment to screenwriters, actors, directors, musicians, and other American entertainment professionals during the mid-20th century because they were accused of havingCommunist ties or sympathies
someone accused of being a communist/communist sympathizer, asked to account both their own and others communist activities, couldnt get work-known for being communist, lives were ruined