Evolution of Search Engines

What Is Search Engine

A search engine is a program available over the internet that searches for the document and files correspond to keyword specified by the user and return the result of any file containing this keyword. the first ever search engine developed is an archive and is used for searching the FTP files. The most popular search engine now-days is Google. Many other search engines available in the market include Bing, Yahoo, Ask.com, AOL, Baidu etc.

Evolution of search engines


Every search engine has 3 main function

  • Crawling
  • Indexing
  • Retrieval


This is the first step in understanding the working of a search engine. It is a process of scanning and collecting information about every page But how’s the Crawling done? An automated bot visits page after page as quickly as possible, using page links to find where to go next.

Google’s spiders could read several hundred pages per second in the earliest days. Nowadays, it’s in the thousands. any site that is linked to an indexing site will be crawled automatically. When a web crawler visits a web page it collects all the links from the page and adds them to its list of next visiting page. Web crawlers also revisit past pages once in a while to see if any changes happened.

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