Graphic Format

Graphic Formats

PNG: The Portable Network Graphics format. Was created to replace GIF for free, it handles 1 to 48 bit images, well-compressed format like GIF. Still not very popular.
GIF: Graphics Interchange Format. Is very good and still a popular picture format. The down side to GIF images is that it can only have 256 colors, or 256 shades of grey, and you can also see a low resolution version of the picture before downloading it.
JPG/JPEG: Joint Photographic Experts Group. Has the file name suffix .JPG, the idea of JPEG is that as it compresses the data it throws some of it away.  
TIFF: Tag Image File Format. Many people say Tagged instead of Tag, which is technically incorrect but minimally important. TIFF was a large, unwieldy, 24 bit format until version 6 came out.

Source: http://www.dansdata.com/graphics.htm#JFIF