The "diff" Utility
Like the "sort" utility, the "diff" utility is a very useful command for manipulating files. The "diff" command allows you to compare files to see if there are any differences between them. This is particularly useful when cleaning up your directory tree or familiarizing yourself with a directory you have not been to in a long time. Note that the "diff3" command allows you to compare three files at once but we will not go over that here.
As you would expect, the diff utility comes with a useful option