An intranet is a private computer network that belongs to a business, university, government agency or other organization and that can be accessed only by authorized persons, typically employees or other members of the organization.
Intranets uses Internet protocols (i.e., TCP/IP) and generally resemble the Internet, including providing similar services such as web sites, file transfer protocol (FTP) and e-mail. The main differences are that the services and resources are protected from unauthorized access through the use of firewalls and other techniques and that the content is specific to that of use to the particular organization.
A major advantage of intranets is that, in contrast to LANs (local area networks), they are not limited to small geographical areas and thus can make it easy for authorized people to access the network from virtually anywhere, such as from home or while traveling. This is accomplished by utilizing the ordinary telephone network (PSTN). Connecting to an intranet resembles connecting to the Internet, except that the user is connecting to a private network instead of to an Internet service provider (ISP).
The main purpose of intranets is usually to share organizational information (e.g., announcements, policies and procedures, employee data, and data about existing and new products) and computing resources among employees and others in the organization. Intranets can also be used to facilitate working in groups, including for teleconferences.
When part of an intranet is made accessible to suppliers, customers or others outside the organization, that part becomes part of an extranet.
Created December 2, 2005.