Processes in Linux and Run Levels

In this lesson, you will learn how Linux starts and manages services under different operating modes.

You will be introduced to traditional Linux run levels, including shutdown mode, rescue mode, multi-user mode, graphical mode, and reboot mode.

You will also learn how modern Linux systems use systemd targets instead of traditional run levels. Important targets such as multi-user.target, graphical.target, rescue.target, and reboot.target will be discussed.

The lesson explains how to check the current default target, change the default system mode, and temporarily switch between systemd targets.

By the end of this lesson, you should understand how run levels and systemd targets control the processes and services that start on a Linux system.