An intranet is a "private Internet" that uses the protocols of the World Wide Web to share information resources within a company or with the company's business partners and clients. The hardware requirements for an intranet begin with a dedicated Web server permanently connected to the departmental network. The heart of a Web server is the hypertext transfer protocol (HTTP) service, which receives a page request from a client's browser and transmits the page back to the client. Although knowledge of hypertext markup language (HTML) is not essential for authoring a Web page, a working familiarity with HTML is useful, as is knowledge of programming and database management. Security can be ensured by using scripts to write information in hidden fields or by means of "cookies." Interfacing databases and database management systems with the Web server and conforming the user interface to HTML syntax can be achieved by means of the common gateway interface (CGI), Active Server Pages (ASP), or other methods. An intranet in a radiology department could include the following types of content: on-call schedules, work schedules and a calendar, a personnel directory, resident resources, memorandums and discussion groups, software for a radiology information system, and databases.