In Geographic Information Systems (GIS), there are two primary types of spatial data: Raster and Vector. Each type represents geographic features and spatial information in a different way.

Raster Data

• Definition: Raster data is a grid of cells (pixels), each with a value representing information, such as temperature, elevation, or land cover.
• Structure: Made up of rows and columns forming a matrix; each cell has a geographic location and a value.
• Best Used For:
  • Continuous data (e.g., satellite imagery, aerial photos, elevation models)
  • Surface analysis (e.g., slope, aspect)
• Examples:
  • Digital Elevation Models (DEMs)
  • Satellite images (e.g., Landsat)
  • Land use/land cover maps
• File Formats: .tif, .img, .jpg, .png, .grd

Vector Data

• Definition: Vector data uses geometric shapes (points, lines, polygons) to represent discrete features.
• Structure:
  • Points: Single x,y coordinates (e.g., trees, wells)
  • Lines: Series of points forming paths (e.g., roads, rivers)
  • Polygons: Closed loops defining areas (e.g., lakes, land parcels)
• Best Used For:
  • Discrete features
  • Network analysis
  • Precise boundaries
• Examples:
  • Administrative boundaries
  • Transportation networks
  • Property parcels
• File Formats: .shp, .geojson, .kml, .gdb

Summary Table