Planning your namespace and domain is an essential first step to a successful implementation of Windows 2000. It is an iterative process that requires a clear understanding of the political vagaries of the organization. A Windows 2000 namespace can have either a single, contiguous, and hierarchical tree structure or a forest of trees in a noncontiguous namespace. All domain controllers have the same authority over a domain, and there can be multiple organizational units within a domain. We continue our focus on planning in Chapter 4; in Chapter 5, we move from planning to installing.