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
Output:

Installed Groups:
   Engineering and Scientific
   MySQL Database
   Editors
   System Tools
   Text-based Internet
   Legacy Network Server
   DNS Name Server
   Dialup Networking Support
   FTP Server
   Network Servers
   Legacy Software Development
   Legacy Software Support
   Development Libraries
   Graphics
   Web Server
   Ruby
   Printing Support
   Mail Server
   Server Configuration Tools
   PostgreSQL Database
Available Groups:
   Office/Productivity
   Administration Tools
   Beagle
   Development Tools
   GNOME Software Development
   X Software Development
   Virtualization
   GNOME Desktop Environment
   Authoring and Publishing
   Mono
   Games and Entertainment
   XFCE-4.4
   Tomboy
   Java
   Java Development
   Emacs
   X Window System
   Windows File Server
   KDE Software Development
   KDE (K Desktop Environment)
   Horde
   Sound and Video
   FreeNX and NX
   News Server
   Yum Utilities
   Graphical Internet
Done

Task: Install all the default packages by group

Install all 'Development Tools' group packages, enter:
# yum groupinstall "Development Tools"