There are multiple system managers which can by possibly running on your Linux system. The current most common system managers are SysV (init), Systemd and Upstart. You may find this short guide to be of use to you, if you are unsure which, system manager is running on your Linux system.
This is a companion discussion topic for the original entry at https://linuxconfig.org/detecting-which-system-manager-is-running-on-linux-system/