It interactively shows you each change that would be added and lets you decide whether it should be staged or not. Down to the hunk level, so you can partially stage a file if you so choose.

Oh, that's neat.

The -p presumably stands for pInteractive with a silent p :)

Ha! It’s actually patch (as in select parts of the patch) though I remember it as partial.

There's -i for interactive, lets you add, patch and reset (unstage).

LOL it might stand for "prompt before"

Ah, that's what magit does by default.

That would be `git add -u/--update`