Firewall

A private computer network that uses Internet technologies to securely share any part of an organization's information or operational systems with its employees. The data on an intranet is behind the company’s firewall, meaning that it cannot be accessed by individuals or other computers that are not part of the organization. Sometimes the term refers only to the organization's internal website, but often it is a more extensive part of the organization's computer infrastructure and private websites are an important component and focal point of internal communication and collaboration.