Searching the Internet

The Internet provides a wealth of information on virtually any topic. The sheer volume of information on the web can make it difficult for users to find specific information. To help users locate information, many websites provide search engines that explore the Internet and maintain searchable records containing information about website content. This sec- tion explains how search engines work and discusses two types of search engines.

Fig. 2.8 | Options in Firefox 2.

Search engines such as Google (www.google.com), Yahoo! (www.yahoo.com), MSN (www.msn.com), AltaVista (www.altavista.com) and Ask.com (www.ask.com) store infor- mation in data repositories called databases that facilitate quick information retrieval. When the user enters a word or phrase, the search engine returns a list of hyperlinks to sites that satisfy the search criteria. Each search engine site has different criteria for nar- rowing searches, such as publishing date, language and relevance. Using multiple search engines may provide the best results in finding the desired content quickly. Sites such as MetaCrawler (www.metacrawler.com) use metasearch engines, which do not maintain databases. Instead, they send the search criteria to other search engines and aggregate the results. Many web browsers, including IE7 and FF2 (Figs. 2.9–2.10.), have a built-in search box placed in the window that can be used to browse the web. In both browsers, the user can choose which search engine to use by clicking the down-arrow menu (Fig. 2.9–2.10).

Search engines can also be used to help resolve programming errors. There are many websites that contain documentation about specific functions, how to use them correctly and related common errors. Putting a function name or error message into a search engine can often help a programmer discover where a mistake may have been made in the code. Also, websites such as www.thescripts.com allow users to post specific programming questions that can be answered by other programmers. Other websites like this one, as well as communities for specific languages, can be found using search engines.

Fig. 2.9 | Searching the Internet with Internet Explorer 7.

Fig. 2.10 | Searching the Internet with Firefox 2.