What is the way to undo a command on Dos?

In DOS (Disk Operating System), there isn't a direct "undo" command like in modern graphical interfaces. However, if you accidentally delete a file, you can try using the "undelete" command if you're using MS-DOS with a compatible file system, but this feature is limited and not always successful. It’s best practice to regularly back up important files to avoid loss, as recovery options in DOS are quite limited.