Microsoft Dynamics 365 Business Unit | Microsoft Dynamics CRM

A business unit is a logical grouping of related business activities.  
A business unit is a unit of the top-level organization. Business units are the foundation of the security structure in Microsoft Dynamics CRM.

1. There is a default business unit that is created when CRM is installed. This is called the root business unit, and it cannot be deleted or disabled–only renamed. 
2. Root business unit (also known as organization) is the top level of a MS Dynamics CRM business unit hierarchy.
3.  You can’t change or disable or delete the root business unit
4.  Each business unit can have just one parent business unit, lookup.
5.  Each business unit can have multiple child business unit.
6.  Users can be assigned to only one BU.
7.  You can assign a team to just one business unit, but a team can consist of users from one or many  business units to work together.
8.  You can’t change the name of a active business unit or delete a business unit after it has been created. You can disable a business unit or change the parent after disabling, however. When you disable a business unit, all users and teams associated with the business unit are also disabled. 
9.  While deleting a business unit, any child Business Units, Users or Teams must be removed either by deleting or reassigning them. It is better to disable a business unit rather than delete it is because once deleted it cannot be undone.
10.  Changing the parent business removes security roles for users and teams associated with the business unit. You must reassign them.

More business units can be created if different levels of access to information is required for different groups within the organization.

Create a new Microsoft Dynamics CRM Business Unit: 

1. On the navigation bar Settings > Security > Business Units

2. On the toolbar click on New. 

3. This will open new business unit create form fill the details and click on save.