Raster Data Model 
04/25/2014 
raster data model See Also: vector data model [data models] A representation of the world as a surface divided into a regular grid of cells.
The Raster Data Model The Raster data model is the simpler of the two and is based on the division of reality into a regular grid of identically shaped cells.
2. Raster data model For each layer, each grid cell (pixel) contains one numeric value:[(01), 0255 (8 bit), 065536 (16 bit), row by row] ...
raster data model A representation of the world as a surface divided into a regular grid of cells.
The raster data model has become the primary spatial data source for analytical modeling with GIS. The raster data model is well suited to the quantitative analysis of numerous data layers.
vector and raster data models field and object data models representations for fields  pointgrids, contours, TIN data models even data structures such as GBF/DIME and chaincodes have been called data models (Peuquet 1990) ...
In this section the implications of vector and raster data models on encoding, storage, and analysis are discussed. The inherent statistical characterizations of mapped data and their implications in map analysis are described.
A DEM held as a regular matrix suffers the same disadvantages due to size as does the raster data model.
Grid layers are graphical representations of the ArcGIS and ArcInfo implementation of the raster data model. Grid layers are stored with a numeric value for each cell. The numeric cell values are either integer or floatingpoint.
While it is recommended that software incorporate both vector and raster data models, priority should be given to vector data model capabilities.
I would suggest you explore the Objectrelational database, the ESRI website, the vector and raster data model, geostatistics or spatial statistics, topology or geospatial topology, and the opengeospatial consortium (OGC) website.
For example, the vector data model represents geography as collections of points, lines, and polygons; the raster data model represents geography as cell matrixes that store numeric values; ...
The raster data model is composed of a grid and each cell within the grid holds data. Another way to explain it is that the polygon has a grid laid over it and the polygon would fill those cells with data, each cell in the grid being assigned a value.
With the raster data model, spatial data is not continuous but divided into discrete units.
See also: GIS, Raster, Raster Data, Data Model, Model
04/25/2014
