都是管理系统服务的命令。service和chkconfig是SysVInit命令，systemctl是Systemd命令。
service
说明：Ubuntu的默认命令
功能：Check/Start/Stop services
示例：service --status-all、service tomcat stop
chkconfig
说明：CentOS 7之前的默认命令
功能：Check/Start/Stop services + Enable/Disable services + Register/Deregister services
示例：chkconfig --list、chkconfig tomcat stop
systemctl
说明：CentOS 7('15~)及之后版本的默认命令，兼容了service命令
功能：Check/Start/Stop services + Enable/Disable services
示例：systemctl list-units、systemctl stop tomcat
扩展资料：https://blog.csdn.net/liumiaocn/article/details/89074418