Bitmap image formats are commonly divided into what is called lossless and lossy. Lossy formats lose image quality when you save them (but they have the advantage of very small file size). Lossless formats do not lose image quality, but they typically have very large file sizes.
BMP The standard lossless bitmap format used by Windows.
TIFF Stands for Tag Image File Format, a lossless cross-platform (both Windows and Macintosh) rasterized file format.
GIF Stands for Graphics Interchange Format developed by CompuServe-Unisys. It is one of the main graphic formats displayed by Web browsers. The GIF format reduces images to a maximum of 256 colors using a special algorithm called Lempel-Ziv-Welch (LZW). Using this algorithm, the GIF format compresses the raw bitmaps into smaller file sizes. Because of their limited color depth, GIFs are better suited for images made from solid colors (such as logos, icons, and buttons) than they are for photos.
PNG (Portable Network Graphics) - An alternative to the GIF format, the PNG format can compress a bitmap without loss. Unfortunately, many web browsers cannot display the lossless PNG, and can only display a lossy indexed version of PNG that is similar to a GIF.
JPEG (also JPG) Stands for Joint Photographic Experts Group. Along with GIF, the JPEG is the other main file format used on the Web. JPEG uses a lossy compression, which means that every time you re-save a JPEG image, some of the original image data will be lost. The JPEG format stores images in 24-bit True Color (GIF uses 8-bit 256 color) allowing your image to have millions of colors. Consequently, JPEGs are better suited than GIFs for photographs and images with fine gradations of tone and color.
Logo saved as a GIF
Logo saved as a JPEG
Photo saved as a GIF
Photo saved as a JPEG
PSD The file format used by Adobe Photoshop. FotoFinish will open all Photoshop files but you will lose any layer information in those files. All visible Photoshop layers will be merged into one flat layer in FotoFinish.