Web server is an application that supports the server side of the Hypertext Transfer Protocol (HTTP), the Internet protocol for the World Wide Web (WWW). Web servers are used to publish content on corporate intranets and over the Internet. To access content on a Web server, you use a Web browser, which supports the client side of HTTP.
Web servers were originally developed on the UNIX platform and were designed for publishing static Web content consisting of ASCII text files formatted using Hypertext Markup Language (HTML). Dynamic content such as forms and search engines were soon added using the Common Gateway Interface (CGI) in scripts written in interpretive languages such as Perl. On Microsoft operating system platforms, Active Server Pages (ASP) and the Internet Server API (ISAPI) are two technologies that you can use to develop dynamic Web content.
An example of a Web server is Internet Information Server (IIS), Microsoft’s Web server for Windows NT Server 4.0. (In Windows 2000 Server, this component is called Internet Information Services.) IIS is a powerful Web application development platform that is managed through a graphical user interface called the Microsoft Management Console (MMC). In addition to supporting HTTP, IIS supports File Transfer Protocol (FTP), Simple Mail Transfer Protocol (SMTP), and Network News Transfer Protocol (NNTP), as well as the Secure Sockets Layer (SSL) and Secure/Multipurpose Internet Mail Extensions (S/MIME) security protocols. IIS also supports Microsoft FrontPage, which is a Web site development tool.
Another popular Web server is Apache, an open source application for UNIX platforms (which has been ported to other platforms as well). Apache was originally based on the National Center for Supercomputing Applications’ httpd Web server daemon, which is no longer being developed. Apache is popular with Internet service providers (ISPs) that were founded within the university environment from which the Internet originated.
Other popular Web servers include Netscape Enterprise Server and Netscape FastTrack Server from Netscape Communications and Lotus Domino, the Web server component of Lotus Notes.