Introduction to the World Wide Web

PRACTICE IN BRIEF 5 • This article explains what the World Wide Web is and how it works. • The main features of Microsoft’s Internet Explorer 7 web browser are described. • The concepts of hyperlinks, uniform resource locator (URL) and domain name system (DNS) are introduced. Introduction to the World Wide Web P. K. Downes1 The World Wide Web used to be nicknamed the ‘World Wide Wait’. Now, thanks to high speed broadband connections, browsing the web has become a much more enjoyable and productive activity. Computers need to know where web pages are stored on the Internet, in just the same way as we need to know where someone lives in order to post them a letter. This section explains how the World Wide Web works and how web pages can be viewed using a web browser. THE INTERNET GUIDE FOR DENTISTRY 1. An introduction to the Internet 2. Connecting to the Internet 3. Introduction to email 4. Effective use of email 5. Introduction to the World Wide Web 6. Creating a practice website 7. Power searching 8. Dental resources on the Internet 9. Safe and efficient use of the Internet 10. Putting it all together; dentistry and the Internet 1General Dental Practitioner, Kelvin House Dental Practice, 2 Nelson Road, Whitstable, Kent, CT5 1DP Correspondence to: Dr Paul K. Downes Email: Refereed Paper © British Dental Journal 2007; 202: 535-540 DOI: 10.1038/bdj.2007.371 THE WORLD WIDE WEB; WHAT IS IT? Although the terms World Wide Web (WWW or simply ‘the web’) and Internet are often used synonymously, they are actually two different things. Think of the Internet as the structure of interconnected computers and the web as the information and resources that are readily available from these computers. The web is the world’s largest store of easily accessible information, most of it freely available. It is composed of at least 11.5 billion1 indexable, interlinked ‘pages’. From these pages you can retrieve documents, view images, animation, and video, listen to sound fi les, speak and hear voice, and run programs. Who creates all these web pages? Academic establishments, commercial businesses, online stores, media groups, governments and organisations have created many of the web resources available today. However, a large chunk of the web still consists of pages created by individual people who have an interest in a particular topic and who want to make their information freely available to any other interested parties. Think of any obscure topic and I’m sure that you will fi nd that a web page has been written about it! Web pages are normally grouped together into ‘sites’; for example, when people talk BRITISH DENTAL JOURNAL VOLUME 202 NO. 9 MAY 12 2007 about the General Dental Council (GDC) website, they mean the collection of web pages produced by the GDC. Each site is normally, but not always, kept on one computer called a web server. Some web servers will play host to many sites. Because of the ease of navigating from one page to another, it is not normally necessary to know on which computer the information is electronically held. WHAT MAKES THE WEB SPECIAL? The web is quite different from more traditional sources of information such as books, magazines, television and video. There are many reasons for this: • Web pages can be joined by ‘hyperlinks’ so that it is easy to jump from one page to another. The link may be between pages on the same site, but it is just as easy to click on a hyperlink and leap to a page on a web server in an entirely different country. A hyperlink normally takes the form of highlighted text (sometimes underlined), or a graphic. As the mouse hovers over a hyperlink, the mouse icon normally turns from an arrow to a pointed fi nger. An email address appearing on a web page can also be a hyperlink; click on it and your email program will automatically open, create a new message and properly address it 535 PRACTICE Fig. 1 The Internet Explorer version 7 toolbar. These icons control the most popular tasks when browsing the web. They are as follows. Navigation icons: (a) back a page, forward a page; (b) go (to the address typed in the address bar); (c) refresh the page, stop downloading the page and the multiple engine search box. Other tasks: (d) home, RSS feeds button (currently greyed-out as the current web page has no feeds), print current page, edit current page, tools for configuration of the browser and help button; (e) favorites and ‘add a favorite’ buttons (screenshots printed with permission from Microsoft Corporation) a b c d e • Because of the way related documents are seamlessly joined by hyperlinks, it can make the process of fi nding further information on a particular topic almost effortless. For example, you may be looking at a page of information about orthodontics, and then by clicking on some text labelled ‘Associations’ you may jump straight to a page that contains a list of orthodontic associations with further hyperlinks to their home pages • It is possible to interact with web pages. Examples include currency converters,2 calculators to fi nd the best deal on Internet service, telephone, gas and electricity providers3 and interactive forms that allow you to specify multiple details when looking for a second hand car4 • The web is becoming a very popular way of buying digital data. Some examples of data being sold on the web include computer programs, updating virus programs, stock digital images for commercial use,5 premium content on business sites6 and music MP3 fi les. Apple sold 70 million songs from its iTunes7 website at 90 cents a time in its fi rst year of business. It also sold one million videos in less than 20 days when it introduced its video download service in October 2005 • It is easy to update the information held on a web page; for example news sites8 and sites that monitor the price of shares9 are continually updated • The web has tools called ‘search engines’ which enable you to search for a keyword, not just within a particular website, but on billions of web pages. The answer to the search is normally returned within a few seconds • You can ‘publish’ your own home/business website and the information it contains is instantly available to anyone with an Internet connection. You would normally upload your created web pages to a web server hosted by your Internet service provider (ISP) • As we saw in the section on email (BDJ 202: 389-393 and 457-461), the web is increasingly being used as a tool for various forms of communication. Webbased email programs, forums, discussion forums, instant messaging and VoIP telephone calls all help people to communicate information and ideas. One of the latest trends is member communities such as Bebo and MySpace. They represent the next generation of social networking where members can stay in touch with their friends (and friends of their friends), share photos and interests or just ‘hang out’. In May 2006, they were the 5th and 6th biggest UK brands (...truncated)