Windows services are long running executable applications that typically do not possess any user interface, are controlled by the Service Control Manager (SCM) and can even be configured to start automatically after the system boots. They typically execute in their own windows sessions. They can execute even if the user has not logged in to the system. They can even be started, paused, re-started manually. These applications are somewhat similar to the daemon processes of UNIX in the sense that they remain dormant most of the time and execute in the background as and when needed.