Search engines have likely become a very important part of your daily routine. You probably use Google, MSN, AOL, or Yahoo! search tools several times a day, along with the search features on your favorite online auction sites.

Some other popular search engines include:

• Altavista: www.altavista.com

• Gigablast: Altavista: http://gigablast.com

• Lycos: Altavista: http://search.lycos.com

• Teoma: Altavista: http://s.teoma.com

Sometimes, you may not give search engines a second thought. Other times, you may wonder how we ever got along without these marvelous tools that can plough through millions, maybe billions, of Web pages in seconds.

When you enter your search term, the search engine's job is to gather, sort, and report the information that seems most relevant to what you are seeking. There are three general types of search engines:

• Spider-based (sometimes called “crawler-based”) search engines

• Search engines that use combinations of online directories and spiders to present their findings

• Online directories built and maintained by people (with help from online search engines, of course)

One example of the third type is the DMOZ Open Directory Project (dmoz.org), which is maintained by a worldwide network of volunteers.