Raster data is a pixel-based data format in which data is stored in a grid structure. Each pixel, or unit of information, has the same size and shape, but varies in value. All digital photographs are stored in this format, including satellite images like those used in the Mapbox Satellite tileset. Raster tilesets are used in Mapbox tools to display maps as a grid of images that can be loaded on the map.
You can upload raster data to your Mapbox account in the GeoTIFF format. The Mapbox Raster Tiles API also allows you to request tiles from a Mapbox-hosted raster tileset.