sudo systemctl
sudo systemctl <start|stop|restart|enable|disable|status> <service>
Risk: Careful
What it does
Talks to systemd, the shift manager: start, stop and check services.
When to use it
A service is down, needs new settings, or must start at boot.
Example
$ sudo systemctl restart nginxRestart the web server with its new settings.
$ systemctl status nginxRunning, stopped or failed, plus the last log lines.
$ sudo systemctl enable --now nginxStart now and at every boot.
Learn it in: Services with systemctl · Official docs