Not so simple! Maps come in all shapes, sizes, and media types...and some don't even look like maps. But they all have a geographical base in common: to navigate by land, sea, or air; to explore for oil, gas, and other mineral resources; to relate information such as a customer base in an geographical information system; or for some other scientific or industrial use such as climate and meteorological studies.
As the geographical base changes either politically or geologically, the maps themselves must reflect the current state. Ships and aircraft require maps showing the current location of hazards and authorized pathways. Subscription map services update subscribers as the maps are revised and published.
Mapping services exist to supply unique maps for real estate ventures, construction projects in unmapped regions of the globe, and other uses for which published sources do not exist.