(1) "Employer" means any person, partnership, firm or corporation employing one or more employees, but does not include the state, or any municipal corporation or political subdivision of the state having in force a civil service system based on merit: Provided, That the term employer shall not include any individual, corporation, business trust, or similar unit whose operations are subject to any federal act relating to equal wages for equal work, regardless of sex.

(2) "Employee" means any individual who, otherwise than as a copartner of the employer or as an independent contractor, renders personal services wholly or partly in this state to an employer who pays or agrees to pay such individual at a fixed rate: Provided, however, That where services are rendered only partly in this state, an individual is not an employee unless his contract of employment has been entered into, or payments thereunder are ordinarily made or are to be made, within this state.

(3) "Wages" means all compensation for performance of service by an employee for an employer whether paid by the employer or another person, including cash value of all compensation paid in any medium other than cash.

(4) "Rate" with reference to wages means the basis of compensation for services by an employee for an employer and includes compensation based on the time spent in the performance of such services, or on the number of operations accomplished, or on the quantity produced or handled.

(5) "Unpaid wages" means the difference between the wages actually paid to an employee and the wages required under section three of this article, to be paid to such employee.