To simplify administration and provide scalability, Microsoft Exchange Server is designed around two basic units ¾ organizations and sites. An organization is the larger administrative unit; it contains all of the servers that provide the messaging functionality for a company. Each organization consists of one or more connected sites. A site is a group of Microsoft Exchange Server computers that share the same directory information and can communicate over high-bandwidth, permanent, and synchronous network connections. If your company has several offices in different cities, the servers for each office can be in different sites.
You can connect sites using a variety of methods, such as wide area networks (WANs), the Internet, or even dial-up lines. Connecting sites enables users in different locations to send messages quickly and efficiently and to exchange information using public folders. It also allows you, the administrator, to manage servers from remote locations and ensure that directory information in all sites is the same.
You can manage your organization and sites using the Microsoft Exchange Administrator program, which you can run on either a Microsoft Windows NT Server or a Microsoft Windows NT Workstation computer. Use the Administrator program to view and configure all of the objects in your organization, such as sites, servers, connections, and message recipients.