Scary? It’s really not that bad. The part to the left of the colon (:) specifies the access method to get to the data. This access method defines the protocol used to communicate with the server, and also gives a good clue as to the type of interaction that will take place. Table 31.1 lists several valid access methods.

Following the :// in the URL is the host name of the server computer you want to contact. After the server name is the directory path to the document you want to view or retrieve. This path depends totally on where the file is located on the remote server. (You might not have a path in some cases, if the file is in a default directory.) Finally, the filename of the document is given. This document can be text, a hypermedia document, a sound file, a graphic, or some other type of file.

So, look again at the example. The following URL

http://www.ncsa.uiuc.edu/SDG/Software/Mosaic/Docs/whats-new.html

uses the HTTP protocol to contact the server computer www.ncsa.uiuc.edu and says that you’re interested in the document named whats-new.html located in the directory /SDG/Software/Mosaic/Docs. The .html extension on the document name tells your Web client (for example, Netscape Navigator) that this document is written in Hypertext Markup Language (HTML). HTML is a special syntax used to write hypertext pages for the Web. For more details on HTML, see Chapter 32, “Creating Web Documents with HTML.”

Searching the Web

The Web is huge, and it’s getting bigger every day. Rather than click through thousands of pages, you can use search engines to help you find information faster. A search engine is a program that looks through its database for information that matches your request. Some search engines, such as AltaVista and Infoseek, search the entire Web and store their information in huge databases. Other search engines search only a specific Web site.

When you see a Search button at a typical Web site, it’s usually only for that Web site. When you want to search the entire Web, you need a more general search tool. The following list describes some of the many search engines that scan Web sites across the Internet. Some even let you search other Internet information sources, like those on Usenet or FTP sites.

•  AltaVista (http://www.altavista.digital.com), for Web and Usenet. You can find anything, anywhere on the Web or Usenet. But you’ll want to narrow your search as much as possible; it is easy to get too many results back!

•  Yahoo! (http://www.yahoo.com), for Web, Usenet, e-mail addresses, current news, people search, city maps, and stocks. Yahoo! isn’t really a search engine. It’s basically a huge list of Web sites, sorted into categories, that have been submitted by users. It’s useful for common information and for getting an idea of just how much—and varied—the information on the Web is. Yahoo! also provides links to search engines.

•  Infoseek (http://www.infoseek.com) for Web, Usenet, FAQs, current news, e-mail addresses, maps, stocks, and company listings. Infoseek contains a search engine and listing service and is good when you want to search more than the Web or Usenet. Infoseek has a different search language than many of the other search engines.

•  Open Text Index (http://index.opentext.net) for Web, Usenet, current news, and e-mail addresses. This is an easy-to-use alternative to AltaVista and is good to use when you need to search for obscure topics. You can also search in other languages, such as Japanese and Spanish.

•  Excite (http://www.excite.com) for Web, Usenet, and Excite Web site reviews. Excite does conceptual searching of the Web and is good when you’re not sure of the exact term you need to search for. Because Excite uses a single-site search engine on many Web sites, it’s free.

•  Lycos (http://www.lycos.com/) for Web, FTP sites, and gopher sites. Lycos has Yahoo!-like features. It’s good for simple searches on common topics. You can search for sounds, graphics, or subject.

•  Search.Com (http://www.search.com/) for Web and Usenet. This search engine also lets you search other search engines such as AltaVista, HotBot, or Infoseek. Search.Com provides an A-to-Z listing of other search engines and has a handy utility to suggest what search engines will find what you need.

•  Inference Find! (http://www.inference.com/) for Web only. Not a search engine itself, Inference Find! groups the results of other search engines and eliminates repeats. As of this writing, it calls WebCrawler, Yahoo!, Lycos, AltaVista, InfoSeek, and Excite.

•  HotBot (http://www.hotbot.com) for Web and Usenet. HotBot is good for finding sites that use a particular technology, such as JavaScript or VRML. You can also narrow your search to a specific geographic location (such as Europe), class of domains (such as edu), or a single Web site (such as www.apple.com).

Good keywords make your search more effective. Come up with words that are unique to what you really want to find. Try to avoid heavily used terms, such as www, Internet, computer, and so on. If you do need them, combine them with other more specific terms and Boolean operators to help narrow your search as in this example:

WWW and “Search Engines”