The crawlers are programs that check the pages for keywords. Well, this is only a general consideration, as the program is more complex than it sounds. It has to check millions of pages at 24 hours, but the majority of pages are visited even often. Google keeps the principles of crawlers secret, and this is the way it should be. There is no method for webmasters to determine all the parameters that are considered by those crawlers, but some of the aspects and the working principles behind those crawlers can be anticipated.
[Read more…] about How On Page SEO Helps to Develop a Crawler Friendly Website