by Dinesh Thakur

According to ecomputernotes - Web crawlers are programs that crawl through the web and collect information for the search engine like google Search Engine.Web Crawlers are also called spider-based search engines,robots, worms.

The crawler name are given because program crawl from page to page in your website and fetch information that search engine like and automatically index website in his database using its own indexing rules or algorithm.

However, The Position of your site in search (popularly called ranking) will depend upon the factors that what a crawler fetch information from your website.That information is display on search result when you search on Google or Some other search engine.If fetched information and searched quote (Searched By user) are matched then search engine display your website on First position in search engine result.

While Positing in the search engine directory or high ranking in search engine result require Some effort in web designing.Conclusion of all thing are that a Search Engine Friendly (SEF) designing make your website in first position and bad design that can create difficulties for crawlers,that keep your website outside the search result.