Auto-Update is enabled by default and tracks minor version updates, e.g. LibreELEC 9.2.0 will update to 9.2.1, 9.2.2, etc. as they are released. It will not perform major version updates as these involve Kodi add-on updates (broken add-ons are the main source of update issues) and user-experience changes we do not want to force onto users. If auto-update is enabled the latest update file will download in the background, then Kodi will prompt you to reboot and start the update process. If you prefer to manage system updates manually, auto-update can be disabled in the settings add-on.