Untracked, staged, unchanged và unstaged là 4 trạng thái chính của một file

Git essentially has 4 main statuses for the files in your local repo:

untracked: The file is new, Git knows nothing about it. If you git add <file>, it becomes:
staged: Now Git knows the file (tracked), but also made it part of the next commit batch (called the index). If you git commit, it becomes:
unchanged: The file has not changed since its last commit. If you modify it, it becomes:
unstaged: Modified but not part of the next commit yet. You can stage it again with git add

As you can see, a git add will track untracked files, and stage any file.

Also: You can untrack an uncommited file with git rm --cached filename and unstage a staged file with git reset HEAD <file>