What is GIS?

GIS stands for Geographic Information Systems:
GIS is a system of hardware and software used for storage, retrieval, mapping, and analysis of geographic data.  GIS also includes the operating personnel and data that goes into the system. Spatial features are stored in a coordinate system (latitude/longitude, state plane, etc.), which reference a particular location on the earth. Descriptive attributes and data are stored in tabular form and are associated with spatial features. Spatial data and associated attributes can then be layered together for mapping and analysis.  GIS can be used for scientific investigations, resource management, and development planning.

Where does the information in the GIS come from?

Muskegon County's GIS uses information gathered from numerous sources, including but not limited to:
Muskegon County Departments
Cities, Townships, and Villages throughout Muskegon County
State of Michigan Center for Geographic Information
US Army Corps of Engineers
US Geological Survey
US Census Bureau