An intranet is a private computer network that uses Internet protocols and network connectivity to securely share part of an organization's information or operations with its employees. Sometimes the term refers only to the most visible service, the internal website.
The same concepts and technologies of the Internet such as clients and servers running on the Internet protocol suite are used to build an intranet. HTTP and other Internet protocols are commonly used as well, such as FTP. There is often an attempt to use Internet technologies to provide new interfaces with corporate "legacy" data and information systems.
Briefly, an intranet can be understood as "a private version of the Internet," or as a version of the Internet confined to an organization. The term first appeared in print on April 19, 1995, in Digital News & Review in an article authored by technical editor Stephen Lawton.
Intranets differ from "Extranets" in that the former are generally restricted to employees of the organization while extranets can generally be accessed by customers, suppliers, or other approved parties.
There does not necessarily have to be any access from the organization's internal network to the Internet itself. When such access is provided it is usually through a gateway with a firewall, along with user authentication, encryption of messages, and often makes use of virtual private networks (VPNs). Through such devices and systems off-site employees can access company information, computing resources and internal communications.
Increasingly, intranets are being used to deliver tools and applications, e.g., collaboration (to facilitate working in groups and teleconferencing) or sophisticated corporate directories, sales and CRM tools, project management etc., to advance productivity.
Intranets are also being used as culture change platforms. For example, large numbers of employees discussing key issues in an online forum could lead to new ideas.
Intranet traffic, like public-facing web site traffic, is better understood by using web metrics software to track overall activity, as well as through surveys of users.
Intranet "User Experience", "Editorial", and "Technology" teams work together to produce in-house sites. Most commonly, intranets are owned by the communications, HR or CIO areas of large organizations, or some combination of the three.
Because of the scope and variety of content and the number of system interfaces, the intranets of many organizations are much more complex than their respective public websites. And intranets are growing rapidly. According to the Intranet design annual 2007 from Nielsen Norman Group the number of pages on participants' intranets averaged 200,000 over the years 2001 to 2003 and has grown to an average of 6 million pages over 2005–2007.