Intranet is a protected neighborhood of computers within the larger city of the Internet.
It is a network of computers within an organization or portion of an organization. Restricting access to an Intranet web site has been the primary security concern for Intranet developers. The simplest way to achieve security is to position the internal web site where it cannot be seen or accessed from the Internet at large - behind a firewall. The security of the Intranet can be enhanced by the security functionality offered by the web servers. For example, user name and password authentication has long been used as a mechanism for restricting access to web sites.