Geography is the science that deals with the study of the Earth and its lands, features, inhabitants, and phenomena.
The use of traditional spatial techniques used in cartography and topography and their application to computers is called geomatics, which encompasses a large area of fields involved with spatial analysis, such as cartography, Geographic information systems (gis), Remote sensing, and Global positioning systems (gps).
The above excerpt is quoted from Wikipedia.
There is a Stack Exchange site devoted to Geographic Information Systems.