An intranet is an internal network that is based on technologies used in the Internet. Specifically, an intranet is, generally, a company-specific network that uses software programs based on the Transmission Control Protocol / Internet Protocol (TCP/IP) used in the Internet and common internet user interfaces such as the web browser. An intranet can be isolated from the Internet by a firewall, as a control of the information that flows into and out of the intranet network

Access to an intranet is restricted to those having permission. In a company setting, these would be the employees, for example. Various levels of authority are possible for those using the intranet. Some people may be granted read-only status, while others have the power to alter information. Finally, a security hierarchy can be implemented, with not all the available information being accessible to all users. This feature can allow public access to the company intranet. A leading courier company, for example, has structured its intranet so that customers are able to access the internal database in order to track the delivery status of their package.

The establishment of an intranet has benefits for a business. One copy of a program can serve multiple users, rather than having to purchase multiple copies of the same program. Information can be exchanged across different computing platforms, unifying communications. Employees can gain access to information stored in multiple locations without labor-intensive and time-intensive searching. Company communications can be distributed over the internal network, eliminated the printing and mail distribution of the information. Finally, communication between employees in geographically disperse locations is enhanced.