A search engine is a device that delivers contents to you as per your query from the World Wide Web. Search engine locates the suitable content from the plethora of information available on WWW in form of links, images and web pages. These engines are based on complex algorithms and sometimes even on human editing.

A search engine uses web crawling, indexing and searching in that order to provide the most accurate results related to a particular search. Search engines work by storing information about millions of web pages that can be retrieved at the request of its user. The web crawler, or “spider,” is used as an automated web browser. It follows every appropriate visible link. The web crawler analyzes the contents of each link to determine how the pages should be indexed.

Descriptions and meta tags are analyzed to determine the type of webpage and its purpose. The meta tags are behind the scenes in the webpage and the viewer never sees them while browsing the page. The search engine uses them as a quick scan to get the idea or theme of the page and then the entire contents of the webpage will be evaluated to ensure the tags are correct and the page is valid.

The major search engines, such as Google amass all, or a miniature portion of the source page, or “cache”, in addition to information the web page offers. The search engine, AltaVista stores every word from every page. Storing the cache helps the search engine filter more easily because web pages are updated constantly. Google’s technique of indexing relieves the “linkrot” and allows users to be sure that the content they find in their search results will be up to date and utilizable. The cache can be helpful when obsolete information is removed. The cache allows users to find and recover information from archived sources.

Cache storage helps in keeping track of the updates on the web page and helps in filtering. The system of indexing used by Google makes sure that only the updated contents are made available to its users by doing away with linkrot. The cache has further usage in finding the updated content that has been removed. It helps in recovering the contents as an archives source. The search process starts with a user keying in some keyword or keyword phrase, related to the content they are looking for, in the search box of an engine. The engine then uses the process of indexing to produce web pages that suit the search phrase the most. The list will include a short description of the contents that each webpage has to offer.

The goal of major search engines is to supply the most relevant results. Not all sites with the requested keywords are relevant to the search. The search engines have used their spiders and indexing to filter out useless information. They generate their own system for analyzing a website for content.

Some search engines use page rankings to assist in their sifting. The search engines look at each individual page and determine through their meta tags, descriptions, keywords and content if the sites are relevant based on the key words in the search. The higher a site is ranked, the higher to the top of the results inventory it will be. The search engine sometimes uses other websites to help determine how highly a site should be ranked. If your page is linked to a higher page, it means that your page will have a higher rank in the search outcome.