Getting Started with Red Hat Enterprise Linux Notes
UNIX, GNU, AND LINUX
Unix: Operating system developed in 1969 for mainframe computers by AT&T.
GNU: Stands for "GNU's Not Unix"; project initiated in 1984 to create a free UNIX-like OS.
Linux: Created by Linus Torvalds in 1991 based on Unix; GNU General Public License allows free use, modification, and distribution.
LINUX KERNEL
Linux: Kernel providing essential services like memory management, security, and scheduling.
Source code available free; modifications must be shared with users.
IS LINUX REALLY FREE?
Free Software Foundation (FSF): Supports GNU project; users can modify and use source code.
Companies can charge for Linux versions, like Red Hat Enterprise Linux (RHEL), often for support.
OPEN SOURCE
Linux licensed under GNU/GPL allows free copying, distribution, and modification.
The license permits selling software without requiring royalties and mandates inclusion of source code.
SOFTWARE DISTRIBUTION
Closed Source: Protects source code, offering only compiled versions.
Public Domain: Free without restrictions on use.
Freeware: Free to use but not necessarily open-source.
Shareware: Free to use but requires payment for extended functionality.
LINUX DISTRIBUTIONS
Red Hat Enterprise Linux (RHEL): Subscription-based, commercially supported.
CentOS: Free version based on RHEL.
Fedora Project: Community-driven platform for new features.
Debian: Community-managed, focuses on user needs.
Ubuntu: Based on Debian; offers commercial support and aims for user-friendliness.
OpenSUSE: Based on the SUSE lineage.
SUPPORTED HARDWARE
Each distribution has Hardware Compatibility Lists (HCLs) available on their websites to check hardware support.
GETTING SUPPORT
Numerous support resources are available online for various Linux distributions, including forums and documentation sites.
DOCUMENTATION
Red Hat Documentation: Available on their official site.
Ubuntu Documentation: Community and official guides available online.
RED HAT DEVELOPERS NETWORK
Free RHEL copy can be downloaded by registering on the Red Hat Developers Network.
RHEL download page available under the developers' section.