Not really visudo is only to edit the sudoers file. sudoedit is a better way to edit system files.
Temporary copies are made of the files to be edited with the owner. set to the invoking user.
The editor specified by the policy is run to edit the temporary files. The sudoers policy uses the SUDO_EDITOR, VISUAL and EDITOR environment variables (in that order). If none of SUDO_EDITOR, VISUAL or EDITOR are set, the first program listed in the editor sudoers(5) option is used.
If they have been modified, the temporary files are copied back to their original location and the temporary versions are removed.
Not really
visudois only to edit the sudoers file.sudoeditis a better way to edit system files.