Controls how systemd terminates processes belonging to the service. This writes KillMode=.

control-group is the default and safest choice: systemd stops the main process and any remaining child processes in the service cgroup. mixed sends the first termination signal only to the main process, then later kills remaining cgroup processes if needed.

process stops only the main process and can leave child processes behind. none makes systemd run the stop command but not kill service processes. Avoid process and none unless you know the application manages its own process tree safely.