Why does git-status suggest different commands to unstage files depending on whether there is a commit yet or not?

After a new repository has been created, before a commit has been made, when files are staged, git-status suggests using git-rm to unstage files: $ git status [...] No commits yet Changes to be committed:   (use "git rm --cached <file>..." to unstage) [...] After a commit has been made, git-status suggests using git-restore instead: $ git status [...] Changes to be committed: (use "git restore --staged <file>..." to unstage) [...] Why is this the case?