What is raster data primarily used for in GIS?

Raster data is primarily used in Geographic Information Systems (GIS) to represent spatial information through a grid of pixels or cells. Each cell has a value that reflects some property of the geographic feature at that location, such as elevation, temperature, or land cover type. This format allows for effective analysis and visualization of continuous data and spatial phenomena across a geographic area.

The use of raster data is particularly significant for displaying features on the Earth's surface because it allows for detailed representation of changes and patterns, such as in satellite imagery or digital elevation models. Raster allows for the visualization of data that varies across different locations, making it a powerful tool for environmental monitoring, urban planning, and resource management.

Other options, while related to geographic data, focus on different aspects. Geographic coordinates are typically represented using vector data, which is more suitable for discrete features like points, lines, or polygons. Maintaining demographic data is often better served by tabular data or vector formats that allow for detailed characteristics associated with specific areas or populations. Calculating distance ratios is frequently performed using vector-based analysis methods that provide precise geometric relationships, rather than through the raster format, which is less accurate for measuring distances due to its pixelated nature.