1) a network connecting an affiliated set of clients using standard internet protocols, esp. TCP/IP and HTTP
2) an IP-based network of nodes behind a firewall, or behind several firewalls connected by secure, possibly virtual, networks

An intranet is the natural evolution of traditional network services. In the last few years, the Internet established a new paradigm for access to information. The intranet borrows this paradigm and applies it on a smaller scale: having an intranet is like having your own internal Web site. The functionality is the same, but the information and pages are ‘internal’ to your organization. In a nutshell, an intranet is a combination of existing LAN and WAN technologies and new Internet technologies. If yours is a typical district, you probably connect to information on your network using several different client applications to access different back-end services such as application communications, host connectivity, and messaging. You probably use one software package for administrative tasks, another for your database, another for e-mail, and another to explore files and documents. Complicating matters further, you may use a combination of PC and Macintosh desktop hardware for accessing these back-end services. Working this way places more demands on the network since each client application uses up bandwidth and memory-never mind the task of managing the network or training teachers and students on many different user interfaces. An intranet enables schools or districts to simplify the data access/multiple-client conundrum. All of the clients required to access multiple data stores can be collapsed into one integrated client-your Web browser. With the right server platform, accessing existing back-end services becomes seamless. Users see a single front-end-HTML pages viewed through a Web browser-and can access information easily and efficiently, thanks to hyperlinks. For example, while storing information has always been easy on file servers, accessing it has not been as simple and just finding the right file is sometimes a challenge. With an intranet, that same content is published as Web pages and is available to everyone who has access rights. Teachers, students, and administrators have a simple way to create and distribute information, and they can edit or update it easily.