THE WORLD WIDE WEB

The World Wide Web began in 1989 as a project by high-energy physics researchers in Switzerland to distribute research Internet to fellow physicists. Since then, the Web has rapidly moved into the forefront of Internet technologies. More people use the Web on the Internet than all other technologies on the Net combined. To most of the general public, the Web is synonymous with the Internet itself and is, in fact, thought by many to have played the dominant role in moving the Internet from an academic research tool to a household word.

The Web is an abstract (imaginary) space of information. On the Web, you find documents, sounds, videos, and information. On the Web connections are hypertext links. The Web uses a writing technology called hypertext. A hypertext is a group of unlinked files. Hypertext is a key concept for understanding today’s Web, but the idea of hypertext originated much earlier than the Web or even the Internet. Two of the most important elements of the Web-Hypertext Transfer Protocol (HTTP) and Hypertext Markup Language(HTML) – contain “hypertext” in their names.

HTTP is a protocol that works with TCP/IP (Transmission Control Protocol/Internet Protocol) to get Web resources to your desktop. A web resource can be defined as any chunk of data that has a URL, such as an HTML document, a graphic, or a sound file. HTTP includes commands called “methods” that help your browser communicate with web servers. GET is the most frequently used HTTP method. The GET method is typically used to retrieve the text and graphics files necessary for displaying a Web page. This method can also be used to pass a search query to a file server. HTTP transports your browser’s requests for a Web resource to a Web server. Next, it transports the Web server’s response back to your browser.

HTML is a set of specifications for creating HTML documents that a browser can display as a Web page. HTML is called a markup language because authors mark up their documents by inserting special instructions, called HTML tags, that specify how the document should appear when displayed on a computer screen or printed.

On today’s Web, many aspects of hypertext have become a reality. A typical Web page is based on a document stored in a file and identified by a unique address called a URL (Uniform Resource Locator). To access any one of these documents, you can type its URL. You can also click an underlined word or phrase called a hypertext link (or simply a “link”) to access related Web pages.

HTTP and HTML are two of the major ingredients that define the Web. If you add URLs, browsers, and Web servers to this recipe, you’ll have a pretty complete menu of the basic technologies that make the Web work.

A web server stores data from Web pages that form a Web site. One way to store data for a Web page is as a file called an HTML document – a plain text, document with embedded HTML tags. Some of these tags specify how the document is to be displayed when viewed in a browser. Other tags contain links to related document, graphics, sound, and video files that are stored on Web servers.

As an alternative to HTML documents, Web servers can store Web page data in other types of files, such as databases. Data from product databases, college course schedules, and music catalogues can be assembled into HTML format “on the fly” in response to Web requests.

To surf the Web, you use Web client software called a browser. When you type a URL into the browser’s Address box, you are requesting HTML data for a specific Web page. Your browser creates a request for the data by using the HTTP “GET” command.

A Web server is configured to include HTTPsoftware. This software is always running when the server is “up” and ready to fulfill requests. One of the server’s ports is dedicated to listening for HTTP requests. When a request arrives, the server software analyzes it and takes whatever action is necessary to fulfill it.

The computer that runs Web software might have other software running on it as well. For example, a computer might operate as a Web server, as an e-mail server, and as an FTP (File Transport Protocol) server all at the same time! To efficiently handle these diverse duties, a computer devotes one port to HTTP requests, one port to handling e-mail, and another port to FTP requests.

A browser is a software program that on your computer and helps you access Web pages. Technically, a browser is the client half of the client/server software that facilitates communication between a personal computer and a Web server. The browser is installed on your computer, and Web server software is installed on servers connected to the Internet.

Your browser plays two key roles. First, it uses HTTP to send messages to a Web server – usually a request for a specific HTML document from Web server, your browser interprets the HTML tags to display requested Web page. Today’s popular browsers are Internet Explorer, Mozilla Firefox, Opera, Google Chrome.

A Web site is a group of related Web pages. The Web site is the master address, and the individual Web pages are like subdirectories to that root directory. Many businesses are creating Web sites for their customers to use. These sites may include price list, information about products, and comparisons of product features with those of competing products. Many sites even allow customers to order products over the Web. Because your site is representing you on the Web, you will want the site to look impressive. For a professional-looking site, you may want to hire a firm that creates Web sites. Such firms employ HTML experts as well as graphic designers and marketing specialists.

Comprehension check. Choose the ending for each sentence from the two versions given.

1. One way to store data for a web page is

a) a file called an HTML document.

b) a unique address called a URL.

2. Some of these tags specify how the document is

a) to be displayed when viewed in a browser.

b) to be identified by a unique address.

3. Business sites may include

a) price list, information about products and comparisons of product features with those of competing products.

b) related document, graphics, sound and video files.

4. HTTP is

a) a protocol that works with TCP/IP to get Web resources to your desktop.

b) a set of specifications for creating HTML documents that a browser can display as a Web page.

5. Your browser creates a request for the data by

a) using the HTTP “GET” command.

b) using Web pages.

6. The Get method can be used to

a) pass a search query to a file server.

b) listen for HTTP requests.