Diff and Patch are traditional commands in the Unix terminal.
But you can also generate patches from a session of BC Text Compare. Once your two files are open in Text Compare, choose from the menu:
Beyond Compare can generate the report...er the patch, in three formats, shown below. Left to right these are Normal-diff, context-diff, and unified-diff:
The +++ and --- don't mean add and subtract. They are just low-res ways to say File One and File Two.