1. SEARCH ENGINES By, CH.KRISHNA MANOJ(Y5CS021), 3/4 B.TECH, VRSEC. 8/7/20151

2. CONTENTS INTRODUCTION TYPES OF SEARCH ENGINES COMPONENTS OF SEARCH ENGINE SEARCH RESULTS IN A SEARCH ENGINE ADVANTAGES DISADVANTAGES FUTURE SEARCH ENGINE 8/7/20152

3. What is a Search Engine? Search : computing to examine a computer file, disk, database, or network for particular information. Engine: something that supplies the driving force or energy to a movement, system, or trend. Search engine: a computer program that searches for particular keywords and returns a list of documents in which they were found, especially a commercial service that scans documents on the Internet 8/7/20153

4. Why is the search engines necessary? With an estimated 800 million web pages finding the one you want is difficult! 8/7/20154

5. Types of Search Engines Three are three types of search engines: 1.Automatic search engines: These rely on "software spiders" to index Web sites. You submit your page to a search engine, and the spider will index your entire site. e.g. Google, Altavista, etc... 2.Classified Directory: These rely on submissions from users and Web site owners to populate their indexes. e.g. Msn, Yahoo!, Aol search,etc...... 3.Meta-Search Engine: These uses the multiple automatic search engines. e.g. Dogpile, Web crawler,etc........... 8/7/20155

6. Components of a Search Engine There are four basic tasks: 1.web crawler(spider or robot): collects pages checks for page changes 2.Indexer: constructs a sophisticated file structure to enable fast page retrieval 3.Searcher: satisfies user queries 4.Ranking results: results ordered from most relevant to least 8/7/20156

7. Search Results Presented as links Supposedly ordered in terms of relevancy to the query Some Search Engines score results Normally organised if groups of ten per page 8/7/20157

8. Role of search engines in the internet The big is getting bigger, and the rich is getting richer. Google -74.8% Yahoo-13.8% msn-6.4% Aol-2.6% Ask-1.2% Others-1.2% 8/7/20158

9. Google architecture URL server sends list of URLs to be fetched to crawlers StoreServer compresses and stores pages Indexer extracts words, their pos., size, capital. Anchors cont.links and their text Sorter generates inverted index Searcher uses Lexicon, II, and PR

10. ADVANTAGES OF SEARCH ENGINES: Very easy to use Normally global The indexes of search engines are usually vast, representing significant portions of the Internet, offering a wide variety and quantity of information resources. The growing sophistication of search engine software enables us to precisely describe the information that we seek. Search engine marketing consists primarily of search engine optimisation and pay-per-click search advertising. 8/7/201510

11. DISADVANTAGES OF SEARCH ENGINES: Links are often out of date Usually too many links are returned Returned links are not very relevant The Engines don't know about enough pages Different engines return different results Rankings are sometimes questionable because they are computer- generated rather than human produced. Lack of human involvement can lead to poor quality control. 8/7/201511

12. Reference books Emery, Vince. How to Grow Your Business on the Internet. 3d Ed. Scottsdale, AZ: Coriolis Group, 1997. Greenberg, Karl. "Search Patterns." Brandweek. September 11, 2000. John, Lauren. "Wanted: As More of the IT Universe Moves to the Web, Search Engines Are Being Used to Take on Increasingly Complex Business Functions." Computerworld. July 3, 2000. Korper, Steffano, and Juanita Ellis. The E-Commerce Book: Building the E-Empire. San Diego, CA: Academic Press, 2000. Regan, Keith. "Does E-Commerce Need Search Engines?" E- Commerce Times. October 18, 2000. 8/7/201512