SysVinitstyle
SysVinitstyle refers to the traditional System V initialization design used by many Unix-like systems. It centers on an init process (PID 1) that governs the system's boot and shutdown sequence through runlevels and a collection of startup scripts. A key feature is the use of a central configuration file, such as /etc/inittab, to declare the default runlevel and basic behavior of the init process.
In the SysVinit style, each runlevel has a set of scripts that control service startup and shutdown.
Booting involves init reading /etc/inittab, determining the default runlevel, and running the appropriate startup scripts. Shutting
Today, SysVinitstyle has largely been supplanted by alternatives such as systemd, Upstart, and OpenRC in many