A geographic information system (GIS) is a computer system
for capturing, storing, checking, and displaying data related to positions on
Earth’s surface. GIS can show many different kinds of data on one map. This
enables people to more easily see, analyze, and understand patterns and
relationships.
Data
in many different forms can be entered into GIS. Data that are already in map
form can be included in GIS. This includes such information as the location of
rivers and roads, hills and valleys. Digital, or computerized, data can also be
entered into GIS. An example of this kind of information is data collected by
satellites that show land use—the location of farms, towns, or forests. GIS can
also include data in table form, such as population information. GIS technology
allows all these different types of information, no matter their source or
original format, to be overlaid on top of one another on a single map.
Putting information into GIS is called data capture. Data that are already in digital form, such as images taken by satellites and most tables, can simply be uploaded into GIS. Maps must be scanned, or converted into digital information.
