1. Linux distribution (1) slackware: SUSE Linux Enterprise Server (SLES)
OpenSuse desktop
(2) debian: ubuntu, deepin (depth), mint
(3) redhat: RHEL: RedHat Enterprise Linux
releases a new one every 18 months Version
CentOS: RHEL-compatible format
Winning the bid Kylin: Winning the bid software
Fedora: A new version is released every 6 months
(4) ArchLinux: Lightweight and concise, follow the KISS principle (keep it simple and stupid) (5) Gentoo: Extreme performance, no Provide traditional installation program, download source code to compile and install software on this machine
(6) LFS: Linux From scratch, self-made Linux
(7) Android: kernel+busybox (tool set)+java virtual machine
2. Relations and differences between different distributions
: All distributions use the Linux kernel; they all need to follow the GPL (General Public License) agreement of GNU;
Difference: Different release versions are composed of different versions of kernels, libraries, and programs;
different release versions use different package managers (SLES, Fedora, openSUSE, centos, RHEL use the rmp package management system, and the package files use RPM as the extension ; Ubuntu series, Debian series use DPKG-based package management system, package files with deb as the extension.)
3. Install Centos7.6 operating system and log in normally
(1) VMware virtual machine configuration, omitted;
(2) Centos installation configuration as shown below:
①Select install CentOS7 to start installing the system; 
②Click Continue by default ; ③Click 
date&time to modify the time zone as Asia/Shanghai; 
④Click on Software, select server with GUI; 
⑤Click on installation, click Done in the upper left corner by default, the others do not need to be changed, then click Begin Installation; 
⑥Then set root (administrator) password and create a new account; 
⑦Finally wait for installation After completion, click reboot, and the system installation is over. 
⑧Login interface
4. Configure environment variables to realize the execution time of the command when the history is executed