In what order should photos be scanned? Heirloom scans your photos in a logical order. This means as close as physically possible to the way you ship them.
TIFF is the acronym for Tagged Image File Format, a digital standard for image files. The TIFF is not as popular as the JPG standard, but the TIFF boasts "lossless" quality and raster graphics features.
PNG is the acronym for Portable Network Graphics, a digital standard for image files. The PNG is not as popular as the JPG standard, but the PNG boasts "lossless" quality and supports better image editing.
A JPG, also called JPEG, is the most popular digital format for photographic image files. JPEG is an acronym for the Joint Photographic Experts Group who first developed this standard for digital photography in 1992. The digital file extension .jpeg and .jpg are interchangeable. Most often you'll see the digital file represented as *.jpg, but most people pronounce the file as a "Jay-Peg" image.