Why 'yum list' command display installed packages only ?

Issue

• Yum list command does not display available packages along with installed packages.
• yum list command display installed packages only.

# yum list
Loaded plugins: security
Installed Packages
Deployment_Guide-en-US.noarch                                                     5.2-11                                                            installed
GConf2.i386                                                                       2.14.0-9.el5                                                      installed
ImageMagick.i386                                                                  6.2.8.0-4.el5_1.1                                                 installed
MAKEDEV.i386                                                                      3.23-1.2                                                          installed
NetworkManager.i386                                                               1:0.7.0-9.el5                                                     installed