diff /dif/ n.
1. A change listing, especially giving differences between
(and additions to) source code or documents (the term is often
used in the plural `diffs'). "Send me your diffs for the Jargon
File!" Compare vdiff. 2.
Specifically, such a listing produced by the diff(1)
command, esp. when used as specification input to the
patch(1) utility (which can actually perform the
modifications; see patch). This is a
common method of distributing patches and source updates in the
Unix/C world. 3. v. To compare (whether or not by use of
automated tools on machine-readable files); see also vdiff, mod.