I found in the documentation there’s a function called FileSystemCompare, which compares two folders and returns the differences. What I’m looking for is something similar, but for text files instead of folders (something like WinMerge, if you can try to use or know it).
If you have a specific challenge/objective and you want help implementing a solution with Mathematica, then just post details of your situation and we can help.
Otherwise, it feels a bit vague to say you’re looking for something similar to something else.