A background process is a that runs behind the scenes (i.e., in the background) and without user intervention. Typical tasks for these processes include logging, system monitoring, scheduling, and user notification.

On a system, this term may be used to either refer to a that does not create a, or a. The former are started just as any other program is started, e.g., via.

Windows services, on the other hand, are started. In and later, they. There is no limit on how much a system service or background process can use system resources.

Indeed, in the family of Microsoft operating systems, background processes are expected to be the principal consumers of system resources. On a or system, a background process or job can be further identified as one whose ID differs from its terminal group ID (TGID). (The TGID of a process is the process ID of the process group leader that opened the terminal, which is typically the login shell. The TGID identifies the control terminal of the process group.) This type of process is unable to receive keyboard signals from its parent terminal, and typically will not send output to that terminal. This more technical definition does not distinguish between whether or not the process can receive user intervention. Although background processes are typically used for purposes needing few resources, any process can be run in the background, and such a process will behaves like any other process, with the exceptions given above.

Main article: In family of, a Windows service is a dedicated background process. A Windows service must conform to the interface rules and protocols of the, the component responsible for managing Windows services.

Windows services can be configured to start when the operating system starts, and to run in the background as long as Windows runs. Or, they can be started manually or by an event. Windows NT operating systems which run in context of three: System, Network Service and Local Service. These Windows components are often associated with Host Process for Windows Services:.

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Since Windows services operate in the context of their own dedicated user accounts, they can operate when a user is not logged on. Before services installed as 'interactive services' could interact with Windows and show a. With Windows Vista, however, interactive services are and may not operate properly, as a result of. The three principal means of managing Windows services are: • Services snap-in for • sc.exe • Daemon [ ]. Main article: From a Unix command line, a background process can be launched using the '&' operator. The utility can resume a suspended job (sending ), running it in the background.

Using the utility will also reconnect standard input its parent terminal, bringing it into the foreground. The jobs utility will list all processes associated with the current terminal and can be used to bring background processes into the foreground. When a ends, via explicit logout or network disconnection, all processes, including background processes, will by default be terminated, to prevent them from becoming. Concretely, when the user exits the launching shell process, as part of shutdown it sends a hangup signal () to all its, to terminate all the processes in the corresponding.

To have processes continue to run, one can either not end the session, or end the session without terminating the processes. A can be used to leave a session running but detach a virtual terminal from it, leaving processes running as child processes of the session; the user can then reattach session later. Or, termination can be prevented by either starting the process via the command (telling the process to ignore SIGHUP), or by subsequently running with the job id, which either removes the job from the job list entirely, or simply prevents SIGHUP from being sent. Prodigy Greatest Hits Rar. In the latter case when the session ends, the child processes are not terminated, either because they are not sent SIGHUP or because they ignore it, and thus become orphan processes, which are then adopted by the process (the kernel sets the init process as their parent), and they continue running without a session, now called. Example [ ] In this example running on, the sleep utility was launched into the background.