Search Engines
The World Wide Web (WWW) is a huge history of distributed information, but can be searched as if the information is presented in a single repository. A web search engine is used to search for information based on keywords entered by the user. Google, Yahoo! and Bing are the most popular search engines today and need no introduction about the way they is used and the way results are presented
What is interesting about search engines is the algorithms that were developed, which contributed to
shaping up the state of the web. Google’s page ranking algorithm was the first of the lot which became
widely used.
It was effective as it ranked the results according to the number of links it had, because
pages had more links than the rest. More advances have resulted in Google’s Map Reduce
framework for parallel processing, which then gave rise to open source Hadoop algorithms
A search engine consists of four functional elements -a spider which traverses the web in the back
ground, and builds an index, which is used to retrieve relevant objects, arranged as per their ranking
It is recognized that web search engine technology is a large subject by itself to warrant a separate
book. This section is just to highlight the reader about the importance of this basic web component and
provide suitable pointers into its study.
