What is the Image Unique ID in Exif info? what is it used for?!
It seems each system could use its own method, so is it still unique between different systems?
Searching online I was able to find this information:
Stolen Camera Finder
Apparently stolen camera finders use this Unique ID and other information to find stolen cameras.
Definition according to the Exif.org website:
"This tag indicates an identifier assigned uniquely to each image. It is recorded as an ASCII string equivalent to hexadecimal notation and 128-bit fixed length."
Also see this similar question on another forum.