Geographic Information Systems
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A Geographic Information System (GIS) is a collection of computer hardware, software, and geographic data for capturing, managing, analyzing, and displaying all forms of geographically referenced information.[1]
There are two primary ways geospatial data is represented - Raster and Vector data formats. Raster datasets consist of rows and columns of cells arranged in a grid format. Each cell contains a numerical value that represents the area covered by the cell. Some examples of raster data are Digital Elevation Models (DEMs) and aerial photographs. Vector data uses points, lines, and polygons to represent features on the earth. Vector data is used to represent more specific features than raster data. Some examples of vector data are well locations, streets, and political boundaries. Vector data is usually overlain on raster data.