An image with a location
A GeoTIFF is a TIFF raster file that can include information about how its pixels relate to locations on Earth. That georeferencing lets compatible GIS software place the raster in a map alongside other spatial data.
What to check in a product
Confirm the coordinate reference system, pixel size, spatial coverage, number of bands, data type and no-data values. Depending on the product, some quality information or supporting metadata may be supplied in separate files.
What the format does not tell you
The file extension alone does not establish the acquisition date, positional accuracy, suitability for a particular analysis or rights to publish and redistribute the imagery. These details come from product metadata, supplier specifications and the applicable licence.
Before you order
Share the software or workflow you plan to use. Ask whether the supplied bands, projection and format match your requirements, and retain the original metadata with the imagery.
Further reading: Open Geospatial Consortium — GeoTIFF standard ↗