Search Engines follow their own criteria for searching the web.Search Engine crawl the web through specific parameters.
In Search Engine crawling , they crawl the web mainly by checking the html codes of pages. They see the meta tags of the page. Depending upon the description they crawl the respective page and it also crawl all the links to that page. So it will collect all the pages and check the duplication of links in the step.
The next step Indexing i.e.,after collecting all the pages, it will index the pages based on the particular phrase or key word in the database and it will arrange pages based on the specific terms and their synonyms.
The next step is Querying i.e., responding to user queries is main aspect of Search Engines. How fast it can respond to the user queries is given main importance. So that , the data should be relevant and appropriate . so that he can visit again and again further in future for any thing. It will respond to the queries with giving options for searching for a particular word or word + some extra.So that it will give flexibility to the users search for a wide info with a single click.
The next step is Ranking i.e., ranking of a site or web page .so it's purely based on the algorithm of the Search Engine it follows. Every search engine follows their own algorithm to rank a website . Mainly the check the Quality Content and meta tags and proper linking of internal pages etc..in ranking a website.
example:- Google is giving ranking to a websites.it's ranking is purely based on their priority and rules they follow.
so we will discuss it later when we discuss about page rank.
