It means that if you can decide in one class action the same issues that would have to be tried in hundreds of repetitive individual trials, the class action will result in a valuable savings of judicial time and resources (also known as judicial economy) and will prevent inconsistent judgments, so is therefore a method superior to the other methods available to decide the cases. Moreover, where you have many class members who have suffered small losses, reducing the likelihood that they could afford to go to court individually against the defendant employer, a class action is a fair way to ensure the laws against discrimination can be enforced.