What is site?

A site is a collection of

one or more well-connected (usually a local area network) TCP/IP subnets. The network between the subnets must be highly reliable and fast (512 Kbps and higher). Although the sites are defined on the basis of location,

they can be spanned over more than one location. A site structure corresponds to the physical environment, whereas a domain is the logical environment of the network. A site can contain single or multiple domains, and a domain can contain single or multiple sites.

Sites are created to physically group the computers and resources for optimizing the network traffic. Administrators can configure Active Directory access and replication technology to take advantage of the physical network by configuring sites. When a user logs on to a network, the authentication request searches for the domain controllers in the same site where the user is located.

A site prevents the network traffic from traveling

on wide area network (WAN) links that are slow.