Linux Beginner (cnetos Linux7) switch command mode and graphics mode __linux

Usually we also call the command mode the terminal interface, terminal or console.

Linux Presets will provide six Terminal to allow the user to log in, switching by using:[Ctrl] + [Alt] + [F1]~[F6] combo button.

How to name these six terminal interfaces, the system will name [F1] ~ [F6] as tty1 ~ TTY6 operating interface environment. That is, when you press [CRTL] + [Alt] + [F1] These three combo buttons, you will enter the terminal interface of the tty1.

Back to the graphic interface just now

CentOS5

[Ctrl] + [ALT] + [F1] ~ [F6]: Command line mode login tty1 ~ TTY6 terminal; [Ctrl] + [ALT] + [F7]: Graphical interface desktop.

CentOS7

[Ctrl] + [ALT] + [F2] ~ [F6]: Command line mode login tty1 ~ TTY6 terminal; [Ctrl] + [ALT] + [F1]: Graphical interface desktop.
CentOS5
In the Linux default login mode, there are two main types, one is the login environment with only command line mode (called Execution Level 3), in which you can have a TTY1~TTY6 terminal interface, but there is no environment without a graphical interface. The other is the graphical interface's login environment (called Execution Level 5), in which you have tty1~tty7. The TTY7 is the default graphics environment that waits for login after the boot completes. If you are using the command line mode to start Linux, the preset tty7 is not something. You can log in with your account at any of the Tty1~tty6 terminal interfaces, and then releaseStartXcommand.
To get startx into effect requires at least a few things to do with the following:
 Your tty7 No other window software is operating (Tty7 must be empty);
 You have to have the X Window system installed, and and X server can be successfully restarted;
 You'd better have window administrator, such as Gnome/kde or the TWM of Yangchun;
The services that  X must have, such as font servers (X font server, XFS), must be started

CentOS7
Because the System preset login interface is different, so want to enter the graphics terminal name may also be different, if the installation preset is the graphical interface, the image interface will appear in the TT 1 interface. If your Linux presets use a text interface, then TT1 and TT6 will be used in command line mode to start the graphical interface in the command line environment, then the graphical interface will appear on the TTY above, for example, you are in the TT3 login system, and then enter the STARTX to start the graphical interface, Then this graphical interface will be generated on the TT3. To get startx into effect requires at least a few things to do with the following:
 Does not start the graphical interface under the other TT
 You have to have the X Window system installed, and and X server can be successfully restarted;
 You'd better have window administrator, such as Gnome/kde or the TWM of Yangchun;
CentOS7 began with the use of years of SYSTEMV service management, that is to say, from this version, there is no "executive level" concept, the new management method using the SYSTEMD model, This model will be a lot of services to the management of the dependencies