【错误记录】Git 使用报错 ( no changes added to commit (use “git add“ and/or “git commit -a“) )

git commit -m "modify file1"

D:\Git\git-learning-course>git commit -m "modify file1"
On branch master
Your branch is ahead of 'origin/master' by 3 commits.
  (use "git push" to publish your local commits)
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
        modified:   file1.txt
no changes added to commit (use "git add" and/or "git commit -a")
D:\Git\git-learning-course>

git commit -a -m "modify file2"