How `git diff` Actually Works: The Myers Algorithm in Plain English (opens in new tab)

You run git diff dozens of times a day. You read the red and green lines, you stage the hunks, you move on. But there's a small algorithmic miracle happening every time: out of the astronomically many ways to describe "how file A became file B," the tool quietly finds one of the shortest ones. That's not a formatting trick. It's a shortest-path search. Once you see it, code review, merge conflicts, and "why did git think I moved this whole block?" all start to make sense. A diff is the shorte...