Attribute data - data describing the feature 2. Raster - A grid is used to represent the study area. Location of features within the grid is depicted by values in the cells overlaying the feature. Vector - Geographic features are depicted by coordinates of points, lines, and polygons. Points represent small features such as nest locations.
Lines represent linear features such as roads and streams.
Polygons represent features such as forests, wetlands, and ecoregions. Most modern GIS systems handle both raster and vector data but usually are designed for one data type. Data layers or overlays. Maintenance and analysis of spatial data Maintenance and analysis of attribute data Integrated analysis of spatial and attribute data Output formatting. Information generated from the GIS and resulting decisions made with that information can be accurate only if the initial data are accurate.