Geographic information is to describe the quantity, quality, distribution features, relevance and number, words, images related to the geography, location and time. Geographic information is spatial information, which is the explanation for geographic characteristics and geographic phenomena. While the geographic data is the symbolized expression for all kinds of geographic characteristics, including spatial location, attribute features and temporal features. Spatial location is identified by the ID on longitude and latitude or girds; attribute data is the description of the location or object; temporal features indicate when the data has been captured or when the geographic phenomena happened. Spatial location, attribute and temporal features are the three main basic elements of geographic information.
GIS (Geographic Information System) is a specific spatial information system, which is a technology captures, stores, manages, calculates, analyzes, displays and describes geography related data on earth under the support of hardware and software systems. GIS processes and manages the geographic spatial data and its relation, including the spatial location data, graphic data, remote sensing data, attribute data, etc. for the use of analysis of the phenomena in a specific area, solving the complicated planning, decide and manage problems.
From the above analysis and definition, we can conclude that:
1. GIS will acquire, organize, store, query, analyze all kinds of geographic information, including their spatial location, shape, distribution and socially, economically related information, in the management, planning and decision making processes.
2. GIS is using computer technologies, it also is comprised of multiple sub-systems, like data acquiring system, data management system, data processing and analysis systems, graphic system, product outputting system, etc. These systems will directly affect the hardware platform, functionalities, efficiency, data processing method and output types of GIS.
3. GIS operates on spatial data, i.e. geographic entities like point, line and polygon. One fundamental feature of spatial data is all the data have been geo-coded so that the data can be described, this is how GIS is different from other information systems, and it is the technological difficulty for GIS.
4. GIS is a database management system which captures, stores, queries and displays spatial location data.
5. GIS itself is a science, a software, a service and a discipline.
GIS can be divided into global, regional and local depending on the study area. Also can be divided into comprehensive and thematic depending on study content.
SuperMap Software Co., Ltd is such company which provides the GIS software that can be used for different study area and contents. And SuperMap has already occupied the first position of Chinese market share for long time.