What type of data does raster primarily consist of?

Raster data primarily consists of grid cells that represent spatial variations in geographic phenomena. Each cell in a raster dataset corresponds to a specific area on the Earth's surface, and the value in each cell indicates the characteristics of that area, such as elevation, temperature, land cover, or any other measurable attribute. This format is particularly effective for representing continuous data, where changes occur gradually over space, allowing for detailed analysis through various GIS applications. The grid structure is essential in modeling spatial relationships and patterns across landscapes, making it an invaluable tool in geospatial analysis and remote sensing.

The other options do not accurately capture the essence of raster data; for example, polygons and lines are characteristics of vector data, textual information does not represent spatial variations, and statistical data points do not inherently embody the continuous nature of raster datasets.