WebSphere quick start (2)

1.3 Basic Web knowledge
World Wide Web and World Wide Web are the core technologies of e-commerce. The idea of Web can be traced back to Tim Berners-Lee at CERN (Centre European pour la Recherche nucleus Aire, or European Laboratory for Particle Physics, European Particle Physics Laboratory) in March 1989) information Management: A Proposal ). This proposal proposes the concept of a distributed hypertext system, aiming to integrate several existing information servers of CERN and provide a simple user interface to access various forms of information. In 1990, Web browsers and Web servers were successively implemented in CERN using object-oriented technology. Berners-Lee and his partners have successfully introduced the basic elements that constitute the Web architecture: communication Protocol HTTP (Hypertext Transfer Protocol and Hypertext Transfer Protocol) between Web servers, Web browsers, and servers, and HTML (Hypertext Markup Language and Hypertext Markup Language) for writing Web documents) and the URL used to identify resources on the Web (Universal Resource Locator, unified Resource Locator ). In 1993, Marc Andreesen of the National Center for Supercomputing Applications at the University of Illinois National Super Computing Application Center (NCSA) and his collaborators published a browser called Mosaic, which is the first robust and easy-to-use browser, it has a friendly graphical user interface. Since then, the Web has grown rapidly into a world-wide inventory of information. In 1994, the W3 Alliance was established under the leadership of Tim Berners-Lee. The organization developed technical specifications and provided reference software to develop Web technical standards and promote interoperability between Web products.
URL (Universal Resource Locator, uniform Resource Locator) is used to uniquely identify resources on the Web, including Web pages and image files (such as gif and jpeg files) audio files (such as au files) and video files (such as mpeg files ). The URL format is: Protocol: // host name <: port number>/identifier (for example, http://www.seu.edu.cn: 80/index.html ). The protocol can be HTTP, HTTPS (Secure Hypertext Transfer Protocol), and FTP. The host name is used to identify the requested server. Ports are usually reserved for different protocols, for example, the FTP and HTTP daemon listen on different ports. The default FTP port number is 21, and the default HTTP port number is 80. The identifier indicates the requested port, which can be a file name (including a path) or an application keyword (such as/cgi-bin/and/servlet/) plus some information (such as a script name and servlet name ). For example, the user typed URL format address (such as http://www.seu.edu.cn: 80/index.html); browser request host www.seu.edu.cn in 80 Port httpservice, and request the server's index.html file; the server accepts the request to get the file; the server returns the file to the browser, and tell the browser that this is an HTML file. The browser displays this page on the display. The protocol used between the browser and the web server is HTTP.