1、CentOS
Package format: rpm package
Installation software: yum
Features: A replica of Red Hat Enterprise Linux (RHEL).
Note: CentOS officials have planned to stop maintaining the CentOS Linux project
2、Debian
Package format: deb package
Installed software: aptitude
Features: Relatively stable system
3、Ubuntu
Package format: deb package
Installation software: apt-get
Features: more user-friendly system configuration
More aggressive software updates
More novice friendly, better ease of use and easier to get started