Both coders and system administrators encounter many cases where text files need to be compared. Every *nix system for the last few decades has included some type of plain-text
diff tool, but this is often not enough. The human brain just doesn’t have the capability/capacity to merge the differences between two files.
My grandfather taught me a very important lesson about manual labor: you let the tool do the work. The same lesson can be applied to other fields. Our brains are trained to quickly pick up on visual cues. I work much more efficiently with a utility that displays differences visually.