The document discusses raster data models in GIS. Raster data models represent geographic space as a grid of cells or pixels, with each cell storing numeric values representing attributes like elevation. Key points: - Raster models use a grid-based structure of rows and columns to store imagery and represent continuous surfaces. - Each cell holds a value like elevation and has a defined spatial resolution (size). - Raster data is used for things like satellite imagery, elevation maps, and representing variables that vary continuously over space.