Protected Class: The groups protected from the employment discrimination by law. These groups include men and women on the basis of sex; any group which shares a common race, religion, color, or national origin; people over 40; and people with physical or mental handicaps. Every U.S. citizen is a member of some protected class, and is entitled to the benefits of EEO law. However, the EEO laws were passed to correct a history of unfavorable treatment of women and minority group members. [0]

[0] https://www.archives.gov/eeo/terminology.html

It's the term used to denote the groups protected by a number of different laws, the individual laws describe the classes specifically. This is all well established law and terminology, and anyone who takes part in any hiring process in the US should be versed in all of this.

You're being intentionally obtuse.

Thanks for the information.