The central task of a network is to make sure that the customers (the users) have everything they need and nothing they don't. What they need includes access to the files, folders, applications, printers, and Internet connections that they require to do their jobs. What they don't need is any trouble getting at what they do need.
The network administrator has additional needs, such as shielding need-to-know material from those who don't need to know and protecting the users from themselves. The key to all of these needs is the configuration of groups, users, and group policies—the topic of this chapter.