How services start in the right order.
In this interactive Linux lesson from Stencel Academy you don't just read — you type real commands like systemctl start app, systemctl status app and watch the machine respond on a live, animated map. It is part of the free How Linux Works course.
Builds on: Boot — the ignition chain.
systemctl list-dependencies app — The dependency graph, drawn as a tree.systemctl enable app — Start this unit automatically at boot.journalctl -u app — Logs for one specific unit.