Process vs Service vs Daemon

프로세스와 서비스(and 데몬)의 차이점 초간단 정리

정의

Process

Process: In computing, a process is the instance of a computer program that is being executed by one or many threads. It contains the program code and its activity. Depending on the operating system (OS), a process may be made up of multiple threads of execution that execute instructions concurrently. Process(computing)/Wiki

Service

Service: In Windows NT operating systems, a Windows service is a computer program that operates in the background.It is similar in concept to a Unix daemon. Windows service/Wiki

Daemon

Daemon: In multitasking computer operating systems, a daemon (/ˈdiːmən/ or /ˈdeɪmən/) is a computer program that runs as a background process, rather than being under the direct control of an interactive user. Daemon (computing)/Wiki

간단 분류

• 프로세스: 프로그램 실행 단위. 인스턴스
• 서비스: 백그라운드에서 실행되는 프로그램
• 데몬: 리눅스판 서비스 PPID(부모의 Process ID)=1

Tip: 프로세스는 서비스/데몬을 포함하는 상위개념임. 서비스를 실행시키는 프로세스도 있음(ex. svchost.exe)

더 공부하기: sysVunit, Upstart, systemd