By default when CRM 2011 is installed a default business unit is created that has the same name as the Organization.  There is the ability to delete unused Business Units from the system from the grid view. Some of the features of Business Units are:

• The names of the Business Units can be changed.
• The name of the root Business Unit can be changed to a different one if required instead of default name.
• In order to delete a Business Unit in CRM 2011, first all the users, teams must be detached (removed) and then the Business Unit must be disabled. After this it can be deleted.