What is an Active Directory (AD) used for?
Active Directory (AD) is used for maintaining a network in an efficient and productive manner. It works similar to a phone book in that it is a list of all the networked devices and information about each in an easily searchable format that allow network administrators to perform their jobs correctly.

What are a domain, forest, and namespace?
Domain – The logical directory components created to manage an organization; acts as a container for organizational units.
Forest – The top-level container within the active directory environment; acts as a collection of domain controllers within an organization
Namespace – Defines the scope of the AD and then breaks off into a forest of names. For example, a namespace could be Google.com with branches going to Maps.Google.com and Mail.Google.com.

Why are contiguous namespaces important when designing a domain structure or model?
A contiguous namespace is important when designing a domain structure or model because it helps to define the exact structure of how everything is laid out. It would be very difficult to confuse the namespace of MapQuest with Maps.Google.com. You can clearly tell that one belongs to namespace MapQuest and one to Google. Without simple organization, there would be chaos.

What are some business considerations or requirements considered in the domain structure planning process?
Some important business considerations or requirements considered in the domain structure planning process should be size, transaction rate or speed, security, uptime (most likely 24x7), administration, and integration into current standard processes and programs.

What three tasks must you complete when using the Windows® interface to create a root domain controller?
The three tasks that must be completed when creating a root domain controlling are selecting the server roles through AD, confirming installation selections, and selecting the right deployment configuration.