what is Geographic Information System (GIS)

Geographic Information System (GIS) is defined as an information system that is used to input, store, retrieve, manipulate, analyze and output geographically referenced data or geospatial data, in order to support decision making for planning and management of land use, natural resources, environment, transportation, urban facilities, and other administrative records.
A computer system for GIS consists of hardware, software and procedures designed to support the data capture, processing, analysis, modeling and display of geospatial data.
The sources of geospatial data are digitized maps, aerial photographs, satellite images, statistical tables and other related documents.
Geospatial data are classified into graphic data (or called geometric data) and attributes (or called thematic data. Graphic data has three elements ; point (or called node), line (or called arc) and area (or called polygon) in either vector or raster form which represent a geometry of topology, size, shape, position and orientation.
The roles of the user are to select pertinent information, to set necessary standards, to design cost-efficient updating schemes, to analyze GIS outputs for relevant purpose and plan the implementation.

What Is GPS?

The Global Positioning System (GPS) is a navigation and precise-positioning tool. Developed by the Department of Defense in 1973, GPS was originally designed to assist soldiers and military vehicles, planes, and ships in accurately determining their locations world-wide. Today, the uses of GPS have extended to include both the commercial and scientific worlds. Commercially, GPS is used as a navigation and positioning tool in airplanes, boats, cars, and for almost all outdoor recreational activities such as hiking, fishing, and kayaking. In the scientific community, GPS plays an important role in the earth sciences. Meteorologists use it for weather forecasting and global climate studies; and geologists can use it as a highly accurate method of surveying and in earthquake studies to measure tectonic motions during and in between earthquakes.

http://scign.jpl.nasa.gov/

What is Geomatics ?

Geomatics is the science and technology of gathering,
analyzing, interpreting, distributing and using geographical
information. Geomatics encompasses a broad
range of technologies that can be brought together on
a common spatial reference system to create a
detailed but understandable picture of the physical
world and our place in it. These technologies include:
• GEOGRAPHIC INFORMATION SYSTEMS;
• GLOBAL POSITIONING;
• REMOTE SENSING;
• DIGITAL MAPPING; and
• CADASTRAL SURVEYING.