/vee'dif/ Visual diff. The operation of finding differences

between two files by eyeball search. The term "optical

diff" has also been reported, and is sometimes more

specifically used for the act of superimposing two nearly

identical printouts on one another and holding them up to a

light to spot differences. Though this method is poor for

detecting omissions in the "rear" file, it can also be used

with printouts of graphics, a claim few if any diff programs

can make. See diff.