The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the east-central interior of North America that connect to the Atlantic Ocean via the Saint Lawrence River. The five lakes are Superior, Michigan, Huron, Erie, and Ontario, and they are in general on or near the Canada–United States border. Hydrologically, Michigan and Huron are a single body of water joined at the Straits of Mackinac. The Great Lakes Waterway enables modern travel and shipping by water among the lakes.

Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non-salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranean rivers and lakes. Fresh water is the water resource that is of the most and immediate use to humans.