The concepts are not that far removed from the Windows NT concepts for service management, where services can be automatic start, manual start, and disabled. T

The concepts are not that far removed from the Windows NT concepts for service management, where services can be automatic start, manual start, and disabled. These are, respectively, "enabled", "disabled", and "masked" in the systemd world. There are some differences in the details, of course. But a "disabled" service can be manually started.