Thumbnails are files that have the “.THM” file extension. These files are saved alongside other file types, such as videos from digital cameras. It is important for these files to stay together or the additional file type might not open correctly in certain programs. Thumbnails contain metadata and very small graphics, which can be difficult to view. Converting the .THM file format to the .JPG file format lets you view the thumbnail in a standard picture viewer. Warnings Writer Bio
