“Changes not staged for commit”是什么意思

改了 calc.py、又新建了 notes.txt 之后：

On branch main
Changes not staged for commit:
  (use "git add ..." to update what will be committed)
  (use "git restore ..." to discard changes in working directory)
	modified:   calc.py

Untracked files:
  (use "git add ..." to include in what will be committed)
	notes.txt

no changes added to commit (use "git add" and/or "git commit -a")

calc.py 那一段的意思是【0】。