Mircosoft Dynamics CRM use Business Unit feature to represent organization hierarchy. In every Dynamics CRM organizational hierarchy, there is one root Business Unit, which is created by Dynamics CRM Server Setup program. The root Business Unit is the top most Business Unit in Dynamics CRM organizational hierarchy. You can create many Business Units under the root Business Unit. The Business Unit can be used to represent subsdiaries, divisions, departments or sections. It's up to you to define. Every organization define the Business Unit diffently.
Business Unit cannot be deleted or renamed. If you have misnamed a Business Unit, very sorry to say you that you have to either continue using the misnamed Business Unit or disable to Business Unit and the create a new Business Unit with the correct name. There is no way you can define rename the Business Unit.
Business Unit that no longer in use or already cease operation can be disabled but cannot be deleted. Business Units can be reorganized by changing the Parent business unit.