Change GUI to NON-GUI mode in CentOS7

The preference for me is to work on a Linux box in a terminal.  However, recently encountered the need for GUI.  I happened to have a CentOS 7 install with GUI, but the default boot will boot into NON-GUI.

GUI to CLI to GUI Commands

# Check the current settings
systemctl get-default

# Change to GUI mode.
systemctl set-default graphical.target

# Change to NON-GUI mode.
 systemctl set-default multi-user.target

# reboot
reboot now

Source(s)