In context|obsolete|lang=en terms the difference between salary and fee
is that salary fee is (obsolete) saline while fee is (obsolete) a prize or reward only used in the set phrase “a finder’s fee” in modern english.
As nouns the difference between salary and fee
is that salary is a fixed amount of money paid to a worker, usually measured on a monthly or annual basis, not hourly, as wages implies a degree of professionalism and/or autonomy while fee is (feudal law) a right to the use of a superior’s land, as a stipend for services to be performed; also, the land so held; a fief.
As verbs the difference between salary and fee
is that salary is to pay on the basis of a period of a week or longer, especially to convert from another form of compensation while fee is to reward for services performed, or to be performed; to recompense; to hire or keep in hire; hence, to bribe.