In brief
git status distinguishes working-tree changes against the index, staged changes against HEAD and untracked files. These are different states, not one automatic publication list.
Useful to know
git status distinguishes working-tree changes against the index, staged changes against HEAD and untracked files. These are different states, not one automatic publication list. [1]
Before committing, inspect what is staged. Editing a file after git add can leave the latest edit unstaged. git status --short is convenient, but its two status indicators still need to be understood.
Sources
For further detail and to check the information: