To check whether the current system runs init or systemd:
ps ax | head -2
For the highest-level status:
systemctl
For status on a specific "unit":
systemctl status httpd.service
To restart a specific "unit":
systemctl restart httpd.service
For the details that went into that "unit":
systemctl show httpd.service
For the highest-level status:
service --status-all
For status on a specific service:
service httpd status
To restart a specific service:
service httpd restart
For the details that went into that service:
vim /etc/rc.d/init.d/httpd