Raster datasets represent geographic features by dividing the world into square or rectangular cells laid out in a grid. Each cell has a value that is used to represent a characteristic of the location. Raster data is commonly obtained from aerial photography, satellite imagery or scanned maps (paper maps scanned electronically). Scanned maps won't normally contain any spatial reference information until they are georeferenced. Georeferencing is the process of assigning spatial coordinates to data that is spatial in nature but has no explicit geographic coordinate system (GCS).

This task sheet will take you through the steps of georeferencing using the georeferencing toolbar in ArcMap.