Getting Help:
Among the most useful commands, especially for those learning Linux, are those that provide help. Two important sources of information in Linux are the on-line reference manuals, or man pages, and the whatis facility. You can access an unfamiliar command's man page description with the whatis command.
Clicking on any of the Linux commands Groups will display the list of Linux command under that group:
01. Filesystems, Files and Directories Manipulation Commands
02. Communication and Networking commands
03. Essential Command For Linux Server Performance
04. LVM (Linux Logical Volume Manager) commands
05. User/groups management commands
06. Security Commands.
07. system information Linux commands
08. Linux Process control command
09. System devices administration Command
10. Program installation command
11. Print Management Command
12. Physical Volume Management Commands
13.Paging space (swap) commands
14. Software Management Commands
15. Backup and Restore Commands
16. installation commands
17. Proccess management command
18. Logical Volume Management commands
About Linux Red Hat:
"Red Hat Linux, assembled by the company Red Hat, was a popular Linux based operating system until its discontinuation in 2004.
Red Hat Linux 1.0 was released on November 3, 1994. It was originally called "Red Hat Commercial Linux" It was the first Linux distribution to use the RPM Package Manager as its packaging format, and over time has served as the starting point for several other distributions, such as Mandriva Linux and Yellow Dog Linux.
Since 2003, Red Hat has discontinued the Red Hat Linux line in favor of Red Hat Enterprise Linux (RHEL) for enterprise environments. Fedora, developed by the community-supported Fedora Project and sponsored by Red Hat, is the free version best suited for home use. Red Hat Linux 9, the final release, hit its official end-of-life on 2004-04-30, although updates were published for it through 2006 by the Fedora Legacy project until that shut down in early 2007."
(http://en.wikipedia.org/wiki/Red_Hat_Linux)
Linux Today
The Linux operating system represented a $25 billion ecosystem in 2008. Since its inception in 1991, Linux has grown to become a force in computing, powering everything from the New York Stock Exchange to mobile phones to supercomputers to consumer devices
