Vector data

Vector data is good for representing categorical and multivariate data. It also has attribute tables where every record or row corresponds to a feature or an object and every column corresponds to different attributes. Vector data has three different types: points, lines, and polygons. Points data normally refers to data collected at some point in space. Points connect to each other to become lines and represent features such as highways, paths of anything, and so on. If those lines add up to make a closed shape, we get a polygon.

One commonly used vector data format is shapefile, which is mainly specific to ArcGIS but is widely used now. Shapefile is used to describe vector features such as points, lines, and polygons. For doing so, shapefile uses three to seven files for a single map file to describe different components such as geometries or shape format, projection, attributes, and so on. In shapefile, a file with an .shp extension represents geometry, an .shx file represents the positional index of the feature geometry, and a file with a .dbf extension represents attribute formats in the dBASE IV format. There are also other files such as .prj for projection, .ixs for geocoding indexes, and some more. But .shp, .shx, and .dbf are essential files for constituting a shapefile for representing vector data.