1. MODULE 1: INTRODUCTION AND DATA STRUCTURE
Definition of GIS
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.
Top Five Benefits of GIS
GIS benefits organizations of all sizes and in almost every industry. There is a
growing awareness of the economic and strategic value of GIS. The benefits of GIS
generally fall into five basic categories:
• Cost Savings and Increased Efficiency
• Better Decision Making
• Improved Communication
• Better Recordkeeping
• Managing Geographically
Selected Definition of GIS
DoE (1987)
A system for capturing, storing, checking, manipulating, analyzing
and displaying data which are spatially referenced to the Earth.
Aronoff (1989)
Any manual or computer based set of procedures used to store
and manipulate geographically referenced data.
Sumant Diwakar

2. MODULE 1: INTRODUCTION AND DATA STRUCTURE
Carter (1989)
An institutional entity, reflecting an organizational structure that
integrates technology with a database, expertise and continuing
financial support over time.
Parker (1988)
A information technology which stores, analysis, and displays
both spatial data.
Dueker (1979)
A special case of information system where the database consists
of observations on spatially distributed features, activities, or
events, which are definable in space as points, lines, and areas to
retrieve data for ad hoc queries and analyses.
Smith (1987)
A database system in which most of the data are spatially indexed,
and upon which a set of procedures operated in order to answer
queries about spatial entities in the database.
Ozemoy, Smith and Sicherman (1981)
An automated set of functions that provides professionals with
advanced capabilities for the storage, retrieval, manipulation and
display of geographically located data.
Burrough (1986)
A powerful set of tools for collecting, storing, retrieving at will,
transformaing and displaying spatial data from the real world.
Cowen(1988)
A decision support system involving the integration of spatially
referenced data in a problem-solving environment.
Koshkariov, Tikunov and Trofimov (1989)
A system with advanced geo-modelling capabilities.
Devine and Field (1986)
A form of MIS that allows map displays of the general information.
Sumant Diwakar