All of the characters are feudal because they live in a feudal society. However, each character represents a distinct social group within that society. You can read about the characters in the eNotes study. Briefly, the characters fall into four categories:
Ecclesiastical or church: Priests, Friar, Prioress, Pardoner, Summoner, Monk, Cleric, Canon's Yeoman, Nun, Parson
Government/military: Reeve, Knight, Manciple, Man of Law, Chaucer
Merchant: Miller, Franklin, Wife of Bath, Shipman, Merchant, Physician
Servant/Commoner: Cook, Squire
I hope this helps!