systemctl service and service management under linux
man service to get: the implementation of a system V style startup scripts
service - run a System V init script
man systemctl get: control systemd system and service manager
systemctl - Control the systemd system and service manager
- systemd : completely replace init, parallel to start the service, and to reduce the overhead on the shell, compared to the traditional System V is a great innovation, already used by most Linux distributions.
init (English: initialization shorthand) is a Unix and Unix-like systems used to produce other programs of all processes. It is a way daemon present, process 1. After the Linux system loads the Linux kernel at boot time, then by the init program loads the Linux kernel, the init program completed by the rest of the boot process, such as running load level, load service, guided Shell / graphical interface and so on. Unix family role (such as System III and System V) init of, and research and BSD Unix derivative version compared to some changes. Most Linux distributions and is compatible with System V, but some distributions, such as Slackware uses a BSD-style, others, such as Gentoo is his custom. Later Ubuntu [1] [2] and some other distributions using Upstart [3] instead of [4] traditional init process. By 2015, most Linux distributions have adopted a new System V alternative systemd and Upstart, but systemd backward compatible with System V.