1. The SysVinit package contains a group of processes that control the very basic functions of your system. SysVinit includes the init program, the first program started by the Linux kernel when the system boots. Init then controls the startup, running and shutdown of all other programs. From Mandrake 9.0 RPM

2. System-V like init. Init is the first program to run after your system is booted, and continues to run as process number 1 until your system halts. Init's job is to start other programs that are essential to the operation of your system. All processes are descended from init. For more information, see the manual page init(8). From Debian 3.0r0 APT