Introductory Terms

When you learn about a new operating system, you will also need to learn new terminology. Here are a few basic terms to become familiar with before you continue reading this manual. You will see these terms often:

• Shell prompt: A software interface (similar to a DOS screen) between the user and the operating system. The shell interprets commands entered by the user and passes them on to the operating system. The shell prompt displays the command line.

• Command line: The place in the shell prompt where commands are typed.

• Command: An instruction given to the computer, most often with the keyboard or mouse.

• Graphical User Interface (GUI): A screen with icons, menus, and panels for the user to click on to initiate functions.

• GNOME and KDE: Two popular GUIs included with Red Hat Linux.

• Panel: A GUI environment toolbar, usually located across the bottom of the screen. The panel contains the main menu button, among other things, and can be customized by the user.

• Root: The root user account is created during installation and has complete access to your system. You must be logged in as root to accomplish certain system administration tasks. User accounts are created so typical user tasks can be done without using the root account, to reduce the chance of damaging your OS.

• su and su -: The command su gives you access to the root account or other accounts on your system. When you su to root, or switch to your root account while still inside your user account shell, you have access to important system files that you can change, or damage, permanently. Logging in with the su - command makes you root within the root account shell. If you log in as root with su -, you have access to certain commands that the su command does not grant. Use caution when you are logged in as root.

• Man page and info page: Man (short for manual) and info pages give detailed information about a command or file (man pages tend to be brief and provide less explanation than info pages). To read the man page for the su command, for example, type man su at a shell prompt (or type info su for the info page). To close one of these pages, press [q].

• X or X Window System: These terms refer to the graphical user interface environments. If you are "in X" or "running X" you are working in a GUI rather than a console environment.

• Console: Console, shell prompt, terminal, "the screen that looks like DOS"  these are all the same thing: a non-graphical interface. This environment has no icons, limited menus, and requires that you type commands to perform tasks, rather than pointing and clicking with your mouse.