Searching is the most popular way to find information on the Web, and search engines, which are online software programs designed to help users locate relevant Web sites, are some of the most highly trafficked sites out there.
They have the capability to search the Internet faster and with more precision than any human could. But with this capability comes a flood of information, only a portion of which will be useful to you.
Understanding how search engines work will help you get the results you want and sort through the irrelevant, misleading results you’ll undoubtedly encounter.
When you enter a keyword (that is, a significant term or phrase related to the Web site you hope to find) into a search engine, you are not searching the entirety of the Web. Rather, you are searching the list of Web sites that the search engine has indexed (which can be in the billions). If the search engine hasn't added a Web site to its index, it cannot include it in the search results. Search engines sift through text on Web pages using computer programs called spiders. "Spiders" crawling on the "Web"; get it?
Spiders are very fast but they can travel only through the hyperlinks that connect Web sites. If a page isn't linked to any other pages, spiders can't find it. The part of the World Wide Web that is not linked is called the "invisible Web" or the "deep Web." It may contain information highly relevant to your search. To find resources on the invisible Web, see the "What is the invisible Web, and how do I find it?" and "How do I find a Web directory?" sections of this guide.
Search engines don't know why you want information—they simply find information according to the words you've entered. These results are not recommendations; search engines don't rank their results by the content of each site. They use mathematical equations (or algorithms) to rank them, and the formula may have little to do with a site's legitimacy or value to you.
Companies have gotten wise to the way that search engines work. This has created an environment where Web pages are created and customized with the goal of appearing near the top of a search engine’s results list regardless of their credibility or usefulness. This practice is called "search engine optimization," and it's one reason that not all of your search results will be relevant or trustworthy.
The "Help," "About," or "Preferences" sections of a search engine site often have helpful tips for using that particular search engine to your advantage. For example, if you’re looking for a definition, Google tells you to add “define:” to the beginning of your keyword. Thus, a search for “define: search engine” in Google will give you a list of definitions for “search engine” from around the Web. Similar tricks are innumerable, and all search engines have them. Google has a complete list of “search operators.”
There is more than one kind of search engine: general search engines, also called “horizontal” search engines, search for all types of information, “vertical” search engines search only within certain topics, “meta” search engines search other search engines. Using the kind that does exactly what you need will improve your search results.