How the Crawler Based Search Engines Work?

Search engine optimization is an internet marketing technique that aims to improve both volume and quality of traffic. If you consider applying SEO technique to boost up your e-business, first you have to learn how the search engines work.

The search engine majors like Google, Yahoo! and Microsoft are all crawler based engines where crawlers perform the search on the basis of a particular algorithm. This function of the search engine is called “spidering of the web”. The users get to see only what the search engines have found.

While crawling over the web pages, the crawlers consider a variety of factors.

If the factors don’t match, then the crawler will not be able to find the pages and as such all the pages can not be indexed by the search engines.
The search engine crawlers can also detect the changes in the web pages which eventually affect the search result.
The distance of pages from the root directory of a site is an example of such factor that determines whether or not a search engine will crawl over the page. The body of the content, the title of the page, the header of the browser are the other important factors affecting the search result.

To ensure indexing, some search engines offer paid inclusion services.

There is a basic difference between the crawler-based search engines and the search engines based on submission services. Sometimes the web pages are linked from other search engine indexed pages and they are found automatically without the requirement of paid submission. The search engines such as Yahoo! on the other hand offer a paid submission service.
This paid service comes with the guarantee of spidering followed by the inclusion in the database. But it can not ensure specific ranking on the search pages. This kind of paid inclusion program requires manual submission and human editorial review to work.

Google Webmaster Tools

However, the Google also offers Google Webmaster Tools, which is a free service. For this, an XML Sitemap feed has to be submitted. The sitemap helps to find all the pages. This tool is particularly suitable for the pages that are hard to be found by automatically following links.
The two main points considered by SEO mechanism are how search algorithms work and what people search for the most. Hence, the bottom line is: knowing how the crawler-based search engine works is all important for the SEO specialists.