Learn to use these new tools to expand your research tools. GIS (geographic information system) is a database of geographic information. Google Earth is an example of a large and very sophisticated GIS application. Essentially, GIS applications are databases of geographic data linked to a myriad of other data. Computer programs allow a variety of options to display and analyze the data. Generally, many applications take the form of a base map display with the ability to overlay data linked to location. A historic GISessentially links spatial data with historic data. Examples include applications that display census data, boundary information, historic maps, locations of ancestors, and much more. In fact, some specialized genealogical applications already exist, such as Map My Family Tree and Family Atlas. There are even smart phone GIS apps such as the Family Nexus.