What is a Geographic Information System (GIS)?

Remember those multi-layered images of the human body from middle school science class, showing the body’s skeletal system, nervous system and so on? GIS is similar. It layers modern geographical maps—of streets, buildings, neighborhoods, even subterranean infrastructure—using 21st century technology.

GIS technology works by linking information stored in databases to a place or location. Users can question the data and present the answers in maps, tables and other graphic representations. Since 80% of all information has a geographic component, the power of GIS can be widely used to support decision-making and problem solving across all sectors—public, private, and not-for-profit.

Why do governments use GIS technology? It is an important tool for determining public policy. In a book about public policy, R.W. Greene says, “The realization is growing that almost everything that happens in a public policy context also happens in a geographic one: transportation planners, water resources studies, education subcommittees, redistricting boards, planning commissions, and crime task forces all must consider questions of where along with the usual ones of how, and why, and how much will it cost. GIS, by answering the first question, helps to answer the others.”