This command lets you list packages in any repository enabled on your system or installed. It also lets you list specific types of packages as well as refine your list with a package specification of any of the package's name, arch, version, release, epoch.
By default 'yum list' without any options will list all packages in all the repositories and all the packages installed on your system. Note: 'yum list all' and 'yum list' give the same output.
yum list available
Lists all the packages available to be installed in any enabled repository on your system.
yum list installed
This is equivalent to rpm -qa. It lists all the packages installed on the system.
yum list extras
This command lists any installed package which no longer appears in any of your enabled repositories. Useful for finding packages which linger between upgrades or things installed not from a repo.
yum list obsoletes
This command lists any obsoleting relationships between any available package and any installed package.
yum list updates
This command lists any package in an enabled repository which is an update for any installed package.
yum list recent
This command lists any package added to any enabled repository in the last seven(7) days.
yum list pkgspec
This command allows you to refine your listing for particular packages.
Please see the YumGroups page on this wiki for information about the above commands.