For the purposes of this Directive:

(a) "unfair terms" means the contractual terms defined in Article 3;

(b) "consumer" means any natural person who, in contracts covered by this Directive, is acting for purposes which are outside his trade, business or profession;

(c) "seller or supplier" means any natural or legal person who, in contracts covered by this Directive, is acting for purposes relating to his trade, business or profession, whether publicly owned or privately owned.