Geographic information system GIS:
A computer-based system that collects, maintains, stores, outputs
, and distributes spatial and descriptive data and information for specific objectives
It helps in planning and making decisions regarding.
In agriculture, urban planning and housing expansion, in addition to reading the infrastructure of any city by creating so-called lay layers.
This system enables us to enter geographical information (maps, aerial photographs, satellite visuals)
and descriptive information (names, tables) to process, store, retrieve, query, analyze spatial and statistical analysis, and display it on a computer screen or on paper in the form of maps, reports, and graphs or through the website. :The term GIS consists of three main components
The spatial component of these systems is the land and the real world from which this information is derived.
It is the product obtained after the process of managing, organizing and extrapolating geographical data.
Computer technology and associated software.
:Comparing GIS with other information systems
Due to the huge amount of information, it has become difficult to deal with, absorb and benefit from it,
unless it is organized, classified, indexed, stripped and reduced to databases that can be dealt with automatically and benefited from without prejudice to its accuracy, validity or significance.
There was a need to devise ways and systems to store and manage this information,
so many types of information management systems appeared, including, for example, information management systems.(MIS) or Data Base and Geographic Information System (GIS)
or Computer Aided Design ( CAD)
As for geographic information systems, some view them in the verbal sense only and believe that they are systems concerned with geographic sciences only,
and others cannot determine the difference between them and the so-called information management systems (databases) used in companies,
banks, travel and tourism offices (such as customer names and addresses, names of employees and their salaries)
The difference between management information systems (MIS) or databases (Data Base) and geographic information systems in a simplified way is that databases are stored and
exchanged information between branches of companies and banks in terms of type and quantity without the possibility of linking the information with its real location on the surface of the globe.
While geographic information systems allow the process of linking information spatially with the possibility of spatial analysis of information.
There are also those who confuse computer drawing systems (CAD) and geographic information systems (GIS), and the difference here is clear that CAD systems (such as Micro Station, AutoCAD) have a high ability to draw and design plans, whether they are from two dimensions 2D or a three-dimensional perspective 3D, but there is not enough ability to link this spatial information with descriptive information or even an analytical ability for descriptive and spatial information, but CAD systems are an important way to enter and prepare drawings for GIS systems.
As some may confuse traditional digital maps with geographic information systems (GIS), maps can be defined as a way to distinguish and represent geographically any feature on the ground and its relationship to other landmarks. The maps lack descriptive information bases accompanying the graphic features or represented on the map.
For example, a geographic information system project for a village consists of several layers, the first of which includes the agricultural land ownership boundary layer, and this layer is represented by a set of closed polygons, while the second layer is allocated to village houses, and the third is to government centers such as schools and hospitals, and these two layers are represented by a set of polygons as well.
The fourth layer includes the wells, and represents a group of points, while the last layer includes the roads passing through that village and is represented by a group of lines