A geographic information system (GIS) is a computer system for capturing, storing, checking and displaying geographic data. Once data has been entered into a GIS, it can be used to produce a wide variety of maps. GIS technology can help us better identify spatial patterns and relationships, profoundly informing our understanding of place. This collection highlights key GIS concepts and features National Geographic Explorers using GIS technology in their work to illuminate and protect the wonder of our world.