yum list

The yum list command will list both installed and available packages.

~]# yum list
openssh-server.x86_64  2.4.6-45.el7.centos.4               @base
openssl.x86_64         2.4.6-45.el7.centos.4               @base
krb5.x86_64            2.4.6-45.el7.centos.4               @updates
nginx.x86_64           2.4.6-45.el7.centos.4               @base
httpd.x86_64           2.4.6-45.el7.centos.4               @base
...

The yum list installed command can also be used to list only installed packages.

~]# yum list installed | grep -i httpd
Installed Packages
httpd.x86_64           2.4.6-45.el7.centos.4               @updates

yum info

The yum info package_name command can be used to view information about a package, regarless if the package is or is not installed on your system.

~]# yum info httpd

Name        : httpd
Arch        : x86_64
Version     : 2.4.6
Release     : 45.el7.centos.4
Size        : 9.4 M
Repo        : installed
From repo   : updates
Summary     : Apache HTTP Server
URL         : http://httpd.apache.org/
License     : ASL 2.0
Description : The Apache HTTP Server is a powerful, efficient, and exensible
            : web server.

yum group info

Yum group info package_name can be used to display information on a group package. 

~]# yum group info package_name

yum provides

Yum provides file_name can be used to determine the package that provides a certain file. 

~]# yum provides /path/to/file

yum install 

The yum install package_name command can be used to install a package.

~]# yum install httpd

yum group install

Package groups can also be installed. Double quotes must be used if there is a space in the group name.

~]# yum group install "group name"
~]# yum group install group-name

yumdownloader 

The yumdownloader command can be used to download but not install a package. The yumdownloader command is included in the yum-utils package. Install yum-utils.

~]# yum install yum-utils

After yum-utils is installed, the yumdownloader command can be used. For example, yumdownloader httpd downloads the HTTPD package.

~]# yumdownloader httpd
Loaded plugins: fastestmirror
Loading mirror speeds from cached host
file * base: mirror.es.its.nyu.edu * extras: mirrors.gigenet.com * updates: mirror.nexcess.net
httpd-version.rpm

The --destdir option can be used to specify a directory other than the present working directory.

~]# yumdownloader --destdir /home/<username>/Downloads httpd

Notice the last line in the yumdownloader output lists the HTTPD RPM. The LS command can be used to verify that the RPM was downloaded.

~]# ls
httpd-version.rpm

Once the RPM has been downloaded, the RPM -i httpd-version.rpm command can be used to install the package.

~]# rpm -i httpd-version.rpm
~]# rpm --install httpd-version.rpm

yum update

The update option updates a package.

~]# yum update package_name

yum remove / yum erase

The remove or erase option will uninstall a package, but not remove the configuration files. There is no difference between remove and erase.

~]# yum remove package_name
~]# yum erase package_name

Add group to remove a group package. 

~]# yum group remove "group name"