20 ILCS 662/10
In this Act:
"Comprehensive plan" means a regional plan adopted under Section 5-14001 of the Counties Code, an official comprehensive plan adopted under Section 11-12-6 of the Illinois Municipal Code, or a local land resource management plan adopted under Section 4 of the Local Land Resource Management Planning Act.
"Department" means the Department of Commerce and Economic Opportunity .
"Land development regulation" means any development or land use ordinance or regulation of a county or municipality including zoning and subdivision ordinances.
"Local government" or "unit of local government" means any city, village, incorporated town, or county.
"Subsidiary plan" means any portion of a comprehensive plan that guides development, land use, or infrastructure for a county or municipality or a portion of a county or municipality.
20 ILCS 662/10