The Internet evolved over the past thirty years from a fledging experiment with four computers into a vast information network that connects millions of microcomputers, minicomputers and mainframe computers. As of 1998, the Internet had more than 100 million users world wide, and that number is growing rapidly.
The Internet is decentralised by design and, remarkably, this anarchy by design works well.
Internet: A collection of local, regional and national computer networks that are linked together to exchange data and distribute processing tasks.
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There are a variety of ways to access the Internet, the most common being through an Internet Service Provider (ISP). An ISP is a company that charges an ongoing fee for providing Internet access to businesses, organisations and individuals. The ISP provides the user with the necessary communications software (such as e-mail) and user account. The user supplies a modem that connects the computer to the user’s phone line. The user’s computer dials the ISP’s computer and establishes a connection over the phone line. Once connected the ISP routes data between the user’s computer and the Internet.
Most ISPs offer dial-up Internet connections and electronic mail access, along with additional services. Some ISPs offer direct access to the Internet without the use of proprietary software.
The Internet connects millions of people through a collection of computer networks.
A connection that uses a phone line to establish a temporary connection to the Internet is referred to as a dial-up connection. When the user’s computer hangs up, the connection is broken. A phone line provides a very narrow pipe for transmitting data. Its typical capacity is only 28.8 thousand bits per second (bps). Using a phone line, the time to transfer the contents of a 680 megabyte CD-ROM would be over 53 hours. More rapid digital data transmission is now available from some telecoms providers in various parts of the world.
The World Wide Web was created in 1990 as an easy-to-use source of information.
World Wide Web: A computer network system that allows users to browse through information available on computers round the world.
The World Wide Web opened the Internet to millions of people interested in finding information. There are over one million Web sites around the world and the number is growing very quickly.
The World Wide Web consists of documents called Web pages that contain information on a particular topic. A Web page might also contain one or more links that point to other Web pages.
Link: A reference to another document in an environment like the World Wide Web, that users can go to directly by clicking on the on-screen reference with the computer’s mouse.
Links make it easy to follow a thread of related information, even if the pages are stored on computers located in different countries.
Every Web page is stored as an HTML (HyperText Markup Language) document.
HyperText Markup Language (HTML): One of the main standards that controls how the World Wide Web works; it is an SGML document type definition that determines how Web pages are formatted and displayed and thus enables information to be exchanged on the World Wide Web.
Standardised General Mark-up Language (SGML): A metalanguage that can be applied to documents in order to maintain their structure and context.
An HTML document contains special instructions called HTML tags that tell a Web browser how to display the text, graphics, and background of a Web page.
Web browsers are used to view Web pages, transfer files between computers, access commercial information services, send e-mail, and interact with other Internet users.
Web browser: A software application that enables a user to locate and view pages on a Web site. Also known as a browser.
To request a Web page the user either types in the URL (Uniform Resource Locator) address or uses a ‘mouse’ to click on a Web page link.
Uniform Resource Locator (URL): The global address of documents and other resources on the World Wide Web. URLs can point to executable files that can be fetched using FTP (file transfer protocol, ftp://) or a Web page that can be retrieved using HTTP (hypertext transfer protocol, http://).
After the http://, the next segment of the address is the server name. The server is the computer and software that make the data available. A Web server, for instance, is a computer that uses Web server software to transmit Web pages over the Internet. Most Web servers have domain names prefixed with WWW. By entering the Web server name, one accesses the site’s home page.
Home page: The main page of a Website. Typically, the home page serves as an index or table of contents to other documents stored at the site (that is, the address).
Website: A location on the World Wide Web.
A home page is similar to the title page and table of contents in a book. It identifies the site and contains links to other pages at the site. The following is an example of a home page belonging to the ICA, viewed using a particular type of browser software called Microsoft Explorer.
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