The staging area is finer than files. It is more like a diff, where you can change parts of a file. For example, I usually use git-add -p to put my changes in

The staging area is finer than files. It is more like a diff, where you can change parts of a file. For example, I usually use git-add -p to put my changes in staging without the debug print statements. I still want to keep them in my working copy.