When you learn about a new operating system, you should also learn
new terminology. This section defines a few basic terms you should
learn. You will see these terms often throughout all Red Hat Enterprise Linux
documentation including the Red Hat Enterprise Linux Step By Step Guide:
Command: An instruction given to the computer,
most often with the keyboard or mouse.
Command line: The space at the shell prompt
where commands are typed.
Graphical Desktop: The most visible area
of a GUI. The desktop is where your user Home
and Computer icons are located. You can
customize your desktop to have special backgrounds, colors, and
pictures to add a personal touch.
Graphical User Interface (GUI): A general
term for interactive windows, icons, menus, and panels which allow a
user to initiate actions such as starting applications and opening
files using a mouse and keyboard.
Icons are small images representing an
application, folder, shortcut or system
resource (such as a diskette drive). Launcher
icons usually refer to application shortcuts.
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). For example, to
read the man page for the su command, type
man su at a shell prompt (or type info
su for the info page). To close man or Info pages, press
Panel: A desktop toolbar,
located across the top and bottom of your desktop (such as
Figure 1-12). The panel contains the
menu and shortcut icons to
start commonly used programs.
Panels can also be customized to
suit your needs.
Figure 1-12. The Desktop Panel
Root: Root is an administrative user
account created during installation that has complete access to the
system.(Root is also known as the superuser.) You must be logged in
as root to accomplish certain system administration tasks, such as
changing administrative passwords and running system configuration
tools. User accounts are created so that typical user tasks can be
done without using the root account, which can reduce the chance of
damaging your Red Hat Enterprise Linux installation or applications permanently.
RPM: RPM stands for RPM
Package Manager and is how Red Hat builds and delivers its
software files. An RPM is a software package file you can install
on your Red Hat Enterprise Linux computer.
Shell prompt: A command line interface
between the user and the operating system (Figure 1-13). The shell interprets commands entered
by the user and passes them on to the operating system.
Figure 1-13. A Shell Prompt
su and su -: The
command su (switch user) gives you access to the
root account or other accounts on your system. When you type
su to 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 if you are not
careful). Logging in with the su - command makes
you root within the root account shell. Use caution when
you are logged in as root.
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.
Although the emphasis throughout this book is on navigation and
productivity using the graphical desktop environment, both the graphical
and shell prompt methods of logging in and using your Red Hat Enterprise Linux system are
discussed for your reference.