Some different types of photo/image file types...
JPEG (or JPG) Joint
Photographic
Experts Group: a type of image file, similar to GIF. Whereas the GIF file format is limited to 256 colors or less, JPEG files use millions of colors and can often be compressed to a smaller kilobyte size, making Web pages load faster.
GIF Graphic
Interchange
Format: A type of image file. GIF files are graphics or pictures, often used on Web pages. Because GIF files contain a maximum of 256 colors, this file format is ideal for simple graphics with minimal shading or color variation. Other types of graphics are better suited for the JPEG file format.
TIFF Tagged
Image
File
Format. A file format commonly used for digital scanned images. Images saved in TIFF format can be used on most computers. Developed by Aldus and Microsoft.
There are many more but these are the ones that come immediately to mind. Can you add to the list?
Lyte