How Search Engines Work?

Search Engine is a big place where you can find so many things which are happening in and outside the world. We are living in a world where you cannot live without internet/search engines. We use search engines for learning, shopping, and entertainment also for business. It is difficult to remember the URL of each and every page or websites, but it is always easier to search through search engines. You just need to go to any of the search engines (Google, Yahoo, Bing, etc) and type the keyword you are searching for, for example, “red shoes”. You will get so many links coming in and just follow any of the links. It looks very simple, isn’t it? How does it work? Any idea???

For all your queries or questions search engines need to answer precisely, for that search engine needs to find the information in the web and secondly it has to be organized. Indexing and Crawling, these are the two main functions of search engines.

Crawling is the process where the search engine bots or spiders are responsible for finding the information available on the internet. Crawlers are a set of programs that will detect new pages on the web through SRC and HREF tags and added to the list of sites to index. Search engines have their own algorithms to show the results in the search engine results page (SERP) from their index.
Search engine spiders keep track of all web servers to crawl and the number of websites hosted. Crawlers will visit all the websites and index all the information like how many pages and what kind of content (text, image, video, etc). Spiders do keep track of all changes made to any website when the link is updated, pages updated, added or deleted.

1. Use XML Sitemap, which will act as a road map of your website and will help in SEO and rank better. They helps search engine to quickly catch the important pages of your website.  
2. Use Robots.txt code to those specific pages of your websites which you don’t want to crawl by the search engine spiders/crawlers.

Indexing is the process in which all the information is discovered by the search engine spiders are structured, sorted and stored. They store only those information like when is created, modified, number of pages, type of content, incoming and outgoing links and a lot more factors that are essential for search engine algorithms.
Why is it necessary to get indexed? The answer is very simple. If your website is not indexed, you will not appear in any search engine results. So that means, the more pages get indexed the more you will appear in search engines.