Red Hat Enterprise Linux (RHEL)

Red Hat Enterprise Linux (RHEL) is a commercial Linux distribution developed by Red Hat.
Red Hat Enterprise Linux is released in server versions for x86-64, Power ISA, ARM64, and IBM Z, and a desktop version for x86-64.


Key Components of the RHEL Family

Red Hat Enterprise Linux (RHEL)

This is the flagship commercial product, developed by Red Hat.
It is tailored for enterprise use with paid subscriptions that provide professional support, security updates, and a defined lifecycle.

Fedora

This is a community-driven, cutting-edge distribution that serves as a testing ground for new features and innovations that may eventually be incorporated into RHEL.

CentOS

Originally a community-supported distribution built from the same open-source source code as RHEL, CentOS provided a free alternative with similar functionality.

CentOS Stream

CentOS Stream is a continuously delivered distribution that serves as the upstream development branch for RHEL.
It is a rolling-release version where development is happening live before it gets released to RHEL customers.

Other Derivatives

Other projects, like AlmaLinux and Rocky Linux, have also emerged as community-driven clones of RHEL, aiming to provide a free, stable alternative with long-term support.



The Shell Environment

The shell is the environment where the user interfaces with the operating system.
Bash is the default command-line shell.
GNOME is the standard graphical shell.

From a graphical shell, a terminal window running Bash can be started.


Features of the Bash Shell

The Bash shell provides many features to make working with the shell easier, such as:

  • Command line completion
  • Command history
  • Variables

Using --help

Use the --help option - this is often the fastest way to get basic information about a command.
Type this command and press Enter to see usage information.


MAN Command

The man command in Linux is used to display the user manual of any command that can be run on the terminal.
It provides a detailed view of the command and its options.

Documentation Sections

Documentation in man is organized in different sections.
For basic administration, the following sections matter most:

  1. Executable programs or shell commands
  2. File formats and conventions
  3. System administration commands

All sections are described in man man.
Use man n intro for an introduction to the topic of a specific section number.