yum list

yum list installed
yum list installed | grep php

yum install <packagename>

yum install --enablerepo=epel,remi,remi-php73

yum check-update

yum update

yum --security update

yum downgrade <packagename>-<version>
yum downgrade <packagename>

yum history list
yum history list all

yum history undo 19

yum remove <packagename>-<version>
yum remove php-7.1.3

yum repolist