The following definitions shall be applied to the terms used in this article:
(1) "Agreement" shall mean contract and shall include renewals and alterations of a contract;
(2) "Political subdivision" shall mean any agency or unit of this State, corporate or otherwise, which is authorized to levy taxes or empowered to cause taxes to be levied;
(3) "Services" shall mean such public and municipal functions as are performed for property in and persons residing within a political subdivision; and
(4) "Project" shall mean any reforestation project, resettlement project or rural rehabilitation project for resettlement purposes of the United States located within a political subdivision and shall include the persons inhabiting such project.