How Search Engines and Directories Work
Anyone who accesses the Internet in search of
information will inevitably head straight for a search engine or a
directory. Most people hold the impression that they are one and the
same, but there are some fundamental differences between search engines
and directories. This article will explore in detail the differences
between search engines and directories.
About Internet Search Engines
A web search engine is essentially a website that allows you to input a
word or phrase related to whatever you are searching for. A series of
relevant results will then be produced, containing links to websites
that might contain what you are looking for. Some of the popular search
engines include Google, Yahoo and Nexplore. The main page of most
popular search engines is exceedingly simple, containing a single entry
field where you can input your query, then click a search button,
whereupon most major search engines will search its database for sites
matching your entry.
A results page will appear with the top 10 website results for your
query, with options to link to the following pages of results as well.
Web search engines make use of various factors when ranking sites, such
as the number of times a relevant word or phrase is used in the text on
the site, how many other sites are linked to it, the number of times
keywords can be found in the site's code, many others. Most of the top
search engines operate in much the same way as each other, although
they may use slightly different criteria in ranking websites.
True search engines work by first using a program known as a crawler or
spider. This program trawls the Internet, following links and indexing
the websites they find in a database. Once a spider program has indexed
a website, the search engine will revisit the site regularly in order
to keep its records updated. Some search engines may even use spider
programs multiple times each day, especially if they think the websites
indexed by the engine need to be updated.
You will find that there are many search engines available that
specialize in searching for other file types or information types. Some
items search engines may specialize in indexing are images, files,
music, and many more. Some search engines are also particularly useful
for finding specific types of sites such as shopping sites.
About Internet Directories
Directories function very differently from search engines. Directories
do not make use of spider or crawler programs. Instead, directories are
usually manually maintained by humans. A directory will usually have an
editor who vets submissions to the directory or else it will have
someone who actively searches the Internet for sites to add to their
listings. Directories may vary in size from the small to the truly
massive. An excellent example of a large directory is http://Dmoz.org. It is a
not-for-profit directory edited completely by volunteers. The Internet
also contains countless smaller directories that specialize in a
particular niche. No matter what you are looking for on the web, you
are bound to find a directory that caters to it.
Comparing Search Engines And Directories
A directory edited by someone will usually contain listings of sites of
higher quality since, unlike a search engine; sites added to a
directory must undergo a manual inspection and approval process. A
directory also separates its listings according to categories -
something search engines do not do. A search engine will contain a
great deal more links than a directory, however, and the results you
find on a search engine are also likely to be fresher.
Whether you decide to make use of a search engine or a directory really
depends on what it is you are searching for and which of them is able
to offer you better results to suit your needs.
Article Source: http://www.articlesbase.com/internet-articles/
About the Author
Seomul Evans is a senior Search Engine
Optimization Services specializing in Top Search Engines and search engine
optimization articles .