Search means to find information from the web. Engine means machine or software. Search engine is a machine or software system which allows the internet user to search information from the World Wide Web.
There are a large number of search engines exists in the web. They are Google, Yahoo, Bing, ask.com,Yandex and so on.
The Function of Search Engine is:
- Web crawling
Search engine uses a program called crawler. The web crawler crawls billions of website and makes an index of the relevant content. Thousands of machines process a large quantity of information very quickly. From the index of the content the crawler makes a rank of each site and returns a result page within half of a second.
When you make a web query to search engine using a keyword for particular information, search engine does the following steps:
- Accept your query
- Analyze your query
- Figure out the word order
- Look up the relevant content under the user keyword in its database
- Relevancy is determined by over 200 factors
- Make results by taking into account everything it knows about you
- Rank the results by doing a strictly judgment to keep the content’s placement in SERP.
- Send the results to your browser
Search engine robot always goes for collecting every page in the web which is relevant to the user’s keyword. It crawls the relevant pages by following the links from one page to other pages and takes a copy of the site to make an index. They collect the pages which contains keyword in the URL, in the title of the site, in meta description, in the body of the content, in the heading tag and so on. Thus the relevancy and popularity of the content is determined by over 200 factors. The factors are as follows: