Supervisor.terminate_child
You're seeing just the function
terminate_child, go back to Supervisor module for more information.
Specs
terminate_child(supervisor(), term()) :: :ok | {:error, :not_found}
Terminates the given child identified by child_id.
The process is terminated, if there's one. The child specification is kept unless the child is temporary.
A non-temporary child process may later be restarted by the supervisor.
The child process can also be restarted explicitly by calling restart_child/2.
Use delete_child/2 to remove the child specification.
If successful, this function returns :ok. If there is no child
specification for the given child ID, this function returns
{:error, :not_found}.