dds The .dds extension file is a DirectDraw Surface format file developed by Microsoft and is used by the multimedia application Microsoft DirectX to store graphics and data in the compressed and uncompressed form.
bmp The bitmap image file format or bmp file for short, is a raster graphics image file. It uses a dot matrix data structure to represent pixelated points of color and to store digital image information. The format optionally supports compression and has wide cross platform support on all the major computer operating systems. Because bmp files are raster graphics files, image resolution is constrained meaning images in this format will not scale without loss in quality. This is in contrast to vector graphics images that can scale to arbitrary resolutions.