7 Definitions

1. RAW (a.k.a Digital Negative) - an image file format used by many high-end and professional digital cameras; are considered to be the best form of image file, since it does not process the picture, leaving total control of the editing to the user; file size is much larger then .JPEG files, but is slightly smaller than .TIF file
2. JPG (Joint Photographic Experts Group) - a file extension for a lossy graphics file. The JPEG file extension is used interchangeably with JPG. 
3. PSD (Photoshop Document) - the default format that Photoshop uses for saving data; a proprietary file that allows the user to work with the images' individual layers even after the file has been saved
4. GIF (Graphics Interchange Format) - a file extension commonly used for images on the web and sprites in software programs; uses lossless compression that does not degrade the quality of the image 
5. TIFF (Tag Image File Format) - a common format for exchanging raster graphics (bitmap) images between application programs, including those for scanner images; can be identified as a file with a ".tiff" or ".tif" file name suffix
6. PNG (Portable Network Graphics) - a file format for image compression that, in time, is expected to replace the GIF that is widely used on today's internet
7. BMP (Bitmap Image) - is Microsoft's preferred image format for rasterized graphics; has little use on the web and there are better formats for saving and storing images (PNG, JPG, TIF, etc.)