What is the meaning of Diff?

Clipping of difference.

Clipping of differential.

Used to trash-talk an opposing team at the end of a game by pointing out a skill difference between some role and the same role on the other team.

Any program which compares two files or sets of files and outputs a description of the differences between them.

The output of a diff program, a diff file.

Abbreviation of differential: the differential gear in an automobile.

Abbreviation of differential: differential of types of white blood cell in a complete blood count.

A difficult route.

To run a diff program on (files or items) so as to produce a description of the differences between them, as for a patch file.

To compare two files or other objects, manually or otherwise.

Abbreviation of different.

A program, historically part of the Unix operating system, which compares two files or sets of files and outputs a description of the differences between them.

Source: wiktionary.org