Search Engines Secrets Exposed: Web Crawlers

[ About This Author :: Request Reprint :: Print Article :: Tell A Friend ]

Search Engines Secrets Exposed: Web Crawlers

By Kevin Grimes
http://www.krgenterprises.net

Anyone who is serious about building wealth on the Internet MUST master the search engines. Therefore, learning how the search engines actually work and how they present information to the customer initiating a search, is key to anyone optimizing their website for search engine indexing.

The most common methods the search engines use to index a site is by using content scanning robots called “Web Crawlers” or “Spiders”.

Search Engines use spiders to index websites. When you submit your website pages to a search engine by completing their required submission page, the search engine spider will index your entire site. A “spider” is an automated program that is run by the search engine system. Spider visits a web site, reads the content on the actual site, reads the site's Meta tags, and also follows the site’s outbound links. The spider then returns all that information back to a central depository, where the data is indexed. It will visit each link you have on your website and index those sites as well. Some spiders will only index a certain number of pages on your site, so don’t create a site with 500 pages!

The spider will periodically return to the sites to check for any information that has changed. The frequency with which this happens is determined by the moderators of the search engine, although there is a metatag within many websites’ header that contains instructions for the crawlers to return in a specified number of days.

A spider creates a file almost like a book; it contains the table of contents, the actual content and the links and references for all the websites it finds during its search, and it may index up to a million pages a day!

Example: Excite, Lycos, AltaVista and Google.

When you ask a search engine to locate information, it is actually searching through the index which it has created and not actually searching the Web. Different search engines produce different rankings because not every search engine uses the same algorithm to search through the indices.

One of the things that a search engine algorithm scans for is the frequency and location of keywords on a web page, but it can also detect artificial keyword stuffing or spamdexing. Then the algorithms analyze the way that pages link to other pages in the Web. By checking how pages link to each other, an engine can both determine what a page is about, if the keywords of the linked pages are similar to the keywords on the original page.

These algorithms are largely a mystery; a deep secret known only to the search engine staff. Huge amounts of money are paid to SEO (search engine optimization) experts (as well as some who claim to be experts) to optimize pages for the highest possible search engine rankings. Top rankings on engines like Google mean market domination for the well optimized site, and that top rank is highly contested, as you can guess!

Discuss this in our Webmaster Forums