The first section of Linux essay

The first section of Linux:
1.GNU: Also known as the Slave program, was launched by Richard Stallman on September 27, 1983. Its goal is to create a completely free operating system. In order to ensure that GNU software is free to "use, reproduce, modify and distribute", all GNU software has an agreement to grant all rights to anyone without any restrictions being imposed on others, the GNU General Public License Public LICENSE,GPL). The concept of "anti-copyright" (or copyleft).
1.1GNU is the recursive abbreviation for "GNU ' s not Unix"
1.2GNU contains 3 agreement terms,
GPL:GNU Universal Public License (GNU License)
Lgpl:gnu a looser Public License (GNU Lesser General public License), formerly known as the GNU Library, Common publicly License (the GNU Universal Common license);
Gfdl:gnu the short form of the Free Document license (GNU documentation License).
(The freedom here is not free, it's not about the price but the use of the software is free for all users)

Second, the GPL is the abbreviation of general Public License, and is an unofficial Chinese translation of the GNU Common Authority. It is not published by the Free Software Foundation nor is it a statutory release of the GNU General public licensed software-only the original version of the GNU General Public License in English has such effect.

YUM: (Full name Yellow dog Updater, Modified) is a shell front-end package manager in Fedora and Redhat and CentOS. Based on RPM package management, can automatically download RPM package from the specified server and install, can automatically handle the dependency relationship, and install all dependent packages at once, without tedious downloading, installing

Four, RedHat,! CentOS: Most businesses are using

V. Command line usage specification (graphical interface affects system resource overhead)

VI. Safety Awareness:

1. The command is reversible, 2. Data can be backed up. 3. A machine with a long time can not be started casually, may not restart. (Plan, data Backup)
4. Login server password (cannot be leaked): Keepass: Triple encryption. 5. Computer Lock screen Add password

The first section of Linux essay