A. Unlike Windows Server 2003, which required you to add most components through the Control Panel Add or Remove Programs applet, Server 2008 is organized around Roles and Features, which you install and manage primarily through the Server Manager interface.
A Role is the server's primary function, such as a domain controller (DC), DNS server, DHCP server, or terminal server. An administrator can dedicate an entire server to one Role or use one computer for multiple Roles. A Feature is a supporting function (e.g., backup capabilities, desktop experience, high availability) typically installed to augment an existing Role.
To add a Role, select the Roles item in the console tree and click the Add Roles link. Doing so will open the Add Roles wizard. Roles consist of one or more Role Services, and the wizard's navigation area dynamically changes as Roles and Role Services are selected. You’ll always know where you are in the installation process, and you can use the navigation pane to jump to enabled stages by clicking the navigation area stage instead of clicking Previous or Next multiple times.
The Role-installation wizard navigation menu updates dynamically as choices are made. So if you select the Terminal Services Role, the navigation menu expands to include a Role Service selection stage. If you select the TS Licensing Role Service, the navigation menu expands again to configuration of the TS Licensing Role Service. The idea of this basic configuration is to get the Role doing something useful as quickly as possible. So, during the installation, major configuration options let you get the Role Service functioning at a basic level upon the completion of the installation.
If the Role or Feature you’re installing is dependent on another Role or Feature, a dialog box will alert you to the dependency and offer an option to automatically add the dependent Role or Feature.
You add features through the Server Manager Features section’s Add Features link. The process is the same as the Roles installation, except that there aren't any Feature Services, nor are there any configuration requirements.