What is the main purpose of the GeoTIFF file format?

The main purpose of the GeoTIFF file format is to serve as a raster graphics format that includes embedded georeferencing information, which allows for the spatial representation of the data on the Earth's surface. GeoTIFF extends the standard TIFF (Tagged Image File Format) by incorporating metadata that contains coordinate reference system information and other spatial attributes. This capability makes it particularly valuable for GIS applications, as it allows users to accurately overlay raster images—such as satellite imagery, aerial photographs, or scanned maps—onto other spatial data layers. By providing both the graphical and spatial context, GeoTIFF facilitates the integration of various types of geographic information, enhancing the analysis and visualization capabilities within a GIS environment.

Other options, while they may mention aspects related to file formats, do not accurately capture the fundamental purpose of GeoTIFF in terms of its functionality for raster data with spatial referencing. For instance, it is not primarily a vector graphics format, nor is it a proprietary format limited to satellite imagery, and it definitely isn't merely a text file with coordinates. GeoTIFF is a versatile tool specifically designed to meet the needs of geospatial data representation.