In olden times we had static runlevels. systemd has mechanisms for more flexible and dynamic control of your system.
Before we get into learning more useful systemd commands, let’s take a little trip down memory lane. There is this weird dichotomy in Linux-land, where Linux and FOSS are always pushing ahead and progressing, and people are always complaining about it. Which is why I am taking all of this anti-systemd uproar with a grain of salt,