31-01-2013, 11:02 AM
SEARCH ENGINE
SEARCH ENGINE.ppt (Size: 1.25 MB / Downloads: 37)
INTRODUCTION
Before search engines were introduced finding required information on web was impossible, Google was the successful company to launch search engine which had made searching web pages in easy and accurate way.
Search engines are classified based on crawlers, spiders, human submissions and combination of two.
Every search engine has many web pages stored on their database but search engines with large number of pages on web are not top search engines. Search engines which will provide accurate information based on requested keyword will be the top search engines.
HISTORY
The first Web search engine was "Wandex", a now-defunct index collected by the World Wide Web Wanderer, a web crawler developed by Matthew Gray at MIT in 1993
The first "full text" crawler-based search engine was WebCrawler, which came out in 1994
Several companies entered the market spectacularly, recording record gains during their initial public offerings. Some have taken down their public search engine, and are marketing enterprise-only editions, such as Northern Light.
WORKING
Without the use of sophisticated search engines, it would be virtually impossible to locate anything on the Web without knowing a specific URL (Uniform Resource Locator),
The first part of the address indicates what protocol to use, and the second part specifies the IP address or the domain name where the resource is located.(www.gmail.com)
The global address of documents and other resources on the World Wide Web.
SPIDERS
To find information on the hundreds of millions of Web pages that exist, a search engine employs special software robots, called spiders or Crawler, to build lists of the words found on Web sites.
When a spider is building its lists, the process is called Web crawling.
After spiders or crawlers find pages, they pass them on to another computer program for "indexing." This program identifies the text, links, and other content in the page and stores it in the search engine database's files so that the database can be searched by keyword.
Tips for effective web searching
Highly specific or topics with unique terms/ many concepts: use the search tools
Go through the ‘help’ pages of search tools carefully
Gather sufficient information about the search topic before searching
Spelling variations, synonyms, broader and narrower terms
Use specific keywords, rare/unusual words are better than common ones
Enter most important terms first - some search tools are sensitive to word order
CONCLUSION:
Search engine plays important role in accessing the content over the internet, it fetches the pages requested by the user.
It made the internet and accessing the information just a click away.
The need for better search engines only increases
The search engine sites are among the most popular websites.