The Features of GIS
A Geographic Information System is a system of computer software, hardware and data, and the personnel that makes it possible to enter, manipulate, analyze, and present information that is tied to a location on the earth’s surface.
The components of a GIS fall into three main categories.
Hardware/Software: Hardware is the computer on which GIS operates. The software runs on a wide range of hardware types, from centralized computer servers to desktop computers used in stand-alone or networked configurations. GIS software provides functions and tools needed to input and store geographic information. It also provides query tools, performs analysis, and displays geographic information in the form of maps or reports. All GIS software packages rely on an underlying database management system (DBMS) for storage and management of the geographic and attribute data. The GIS communicates with the DBMS to perform queries specified by the user.
Data: Data is one of the most important, and often expensive, components of a GIS. Geographic data and related tabular data can be collected, purchased from a commercial data provider, or downloaded for free from a number of sources. PASDA, which is the official spatial data clearinghouse for Pennsylvania (www.pasda.psu.edu) provides GIS data free of charge. There are two types of data used in GIS: Vector (points, lines and polygons) Raster We will explain these in further detail later in the basics.
People: The people who are trained to manage the system and develop plans for applying real-world problems are what make a GIS so powerful. There is a wide range of users from a technician and analysts who use GIS for their everyday work, or a specialist who may design and maintain a system.