List all installed packages, enter:
# rpm -qa
# yum list installed
Find out if httpd package installed or not, enter:
# rpm -qa | grep httpd*
# yum list installed httpd

Task: Check for and update specified packages

# yum update {package-name-1}

Task: Install the specified packages [ RPM(s) ]

Install package called httpd:
# yum install {package-name-1} {package-name-2}
# yum install httpd

Task: Remove / Uninstall the specified packages [ RPM(s) ]

Remove package called httpd, enter:
# yum remove {package-name-1} {package-name-2}
# yum remove httpd

Task: Display the list of available packages

# yum list all

Task: Display list of group software

Type the following command:
# yum grouplist