Graphic file formats employ varying compression schemes, and some are designed to work better
than others for certain types of graphics. The two primary Web file formats are GIF and JPEG.
A third format PNG has been available since 1995 but has been little used because of poor browser support.

GIF is " Graphics Interchange Format "
JPEG is "Joint Photographic Experts Group"
It supports 24 bits of color information, and is most commonly used for photographs and similar continuous-tone bitmap images.

PNG is "Portable Network Graphics