
Well, GIF stands for Graphics Interchange Format and was put forth by
Compuserve back in 1987(?) or so.  It was to create a format that could be
read and displayed by any system.  GIF is limited to 8 bit color but has
a built in compression scheme (LZW?).

IFF is not really a graphics format, but rather a standard way to package
images, sounds, animations, text, or whatever into one file.  IFF was
created by Electronic Arts, I do believe (I could be wrong), for the Amiga.
It was quickly adopted as pretty much the standard file format for the Amiga.
The most common image format for the IFF package is an ILBM (InterLeaved
BitMap?) but many others exist.  This format supports 24 bit color images.

Information on both of these and many more are available via anonymous ftp at
zamenhof.cs.rice.edu in the directory /pub/graphics.formats
(Taken from the FAQ for this news group.)  :)