A set of regularly spaced and contiguous cells with associated field values. The values represent cell values, not point values, and a cell value is assumed valid for all locations within the cell. What is this data model called?

• A. Vector
• B. Raster
• C. Grid
• D. Pixel Map

Answer: (B)

This is the raster data model. In raster, space is divided into a regular grid of cells (or pixels), and each cell holds a single value that represents the field over the entire cell. The assumption that a cell value applies to every location within that cell is what makes it different from describing data at points or along features. This structure is ideal for modeling continuous surfaces like elevation, temperature, or rainfall, where values are naturally assigned to areas rather than precise points. The data are stored as a 2D array with a defined cell size and geographic extent, enabling straightforward sampling and spatial analysis on a grid. In contrast, vector data describe space as discrete features (points, lines, polygons) with attributes tied to those features rather than uniform values across areas. A term like “grid” is generic, and “pixel map” is a lay term, but the formal data model for this grid-of-values approach is raster.