GIS is a technological field that incorporates geographical features with tabular data in order to map, analyze, and assess real-world problems. The key word to this technology is Geography – this means that the data (or at least some portion of the data) is spatial, in other words, data that is in some way referenced to locations on the earth. Coupled with this data is usually tabular data known as attribute data. Attribute data can be generally defined as additional information about each of the spatial features. An example of this would be schools. The actual location of the schools is the spatial data. Additional data such as the school name, level of education taught, student capacity would make up the attribute data. It is the partnership of these two data types that enables GIS to be such an effective problem solving tool through spatial analysis. (http://gislounge.com/what-is-gis/ )
A geographic information system (GIS) integrates hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information.
GIS allows us to view, understand, question, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts.
A GIS helps you answer questions and solve problems by looking at your data in a way that is quickly understood and easily shared.
GIS technology can be integrated into any enterprise information system framework. (http://www.gis.com/content/what-gis)
A Geographic Information System (GIS) is a computer-based tool for mapping and analyzing things that exist and events that happen on earth. GIS technology integrates common database operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps. These abilities distinguish GIS from other information systems and make it valuable to a wide range of public and private enterprises for explaining events, predicting outcomes, and planning strategies. (http://devplan.kzntl.gov.za/MapsGis/WhatIsGis.asp)
Simply put, a GIS combines layers of information about a place to give you a better understanding of that place. What layers of information you combine depends on your purpose—finding the best location for a new health service, analyzing environmental crises, viewing similar disease areas in a city to detect a pattern, and so on. GIS can be used to manage, analyze and present Information about geographically located features, for example such information that can be presented on maps. Such information can be about polluting leakage, nurseries and roads, but also about individuals, vehicles and other things with a defined location. GIS can also be used to deal with other types of information that can be linked to a map. (http://gis.emro.who.int/)
What is geographic information?
Geographic information is simply information that expresses and describes the locations of objects and features. It relates to the distribution and patterns of physical and human features that exist on the Earth’s surface.
Types of geographic information are as wide and varied as the field of Geography itself, from socio-economic or demographic data to physical and environmental data. It is usually treated as separate individual ‘themes’ of similar types of information.
These could be physical features such as rivers, roads, forests, erosion, floods, vegetation etc. or human features such as population, migration, administrative areas or regions, poverty, health services, community services etc. (http://www.gis.rgs.org/1.html)