A search engine is a program that indexes web pages based
(mainly) on the content of the web site. It allows you to enter
a key word or phrase into a search engine (like Google) and
be presented with many, sometimes 100's of thousands, of web
sites that relate to your key word or phrase.
For search engines to be useful they have to index the web
well before you type in your search criteria. They do this by
continuously "spidering" the web. "Spidering" is
the term given to using automated programs to "visit" web
sites in order to categorise there appropriateness to show up
in searches using various
keywords.
Search engines are very sophisticated in what they do,
google for example looks at over 100 criteria in order to categorise
a web site. Find out more about how
search engines work here.
Search engines fall in and out of vogue based on how they rate
against other search engines for retrieving appropriate web
pages. As the technology changes so does the most popular search
engine, at the moment Google ranks supreme, with about 80% of
the worlds search going through it. MAny people have a favourite
search engine (usually the one installed as a default on their
computer or the one they first used) but there are new challengers
all the time, try for example www.alltheweb.com or
www.webwombat.com.au for
searches with an Australian bent, or the latest and greatest www.teoma.com. |
