Nudge is a utility that will compare a Mac's currently installed version of macOS against the required version of macOS AppState requires the user to run. If there is a difference in operating systems version, the Nudge window will launch and prompt the user to run Software Updates

The prompt will show up every 75 minutes and the user can defer the updates until the hard set deadline. Within 3 days of the deadline, the nudge window will appear more frequently. After the deadline has past, if the user has not updated the macOS, Nudge window will stay persistent, the user will no longer have the option to defer (LATER button will be removed)  and Nudge will come to the front of the Desktop every 30 seconds until the updates are run.