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  1. 1. Name- Google, because itis a common spelling of googol, or 10100 and fits wellwith our goal of building very large-scale search
  2. 2. 1. Google is a prototype of a large-scale search engine which makes heavy use of the structure present in hypertext.2. Google is designed to crawl and index the Web efficiently and produce much more satisfying search results than existing systems.3.large-scale search engine which addresses many of the problems of existing systems. It makes especially heavy use of the additional structure present in hypertext to provide much higher quality search results
  3. 3. How Google WorksGoogle consists of three distinct parts, each of which is run on adistributed network of thousands of low-cost computers and cantherefore when we enter a query.1.carry out fast parallel processing -Parallel processing is a method of computation in which manycalculations can be performed simultaneously, significantly speedingup data processing.2. Googlebot- a web crawler that finds and fetches web pages. The indexer that sorts every word on every page and stores theresulting index of words in a huge database.3. The query processor, which compares your search query to theindex and recommends the documents that it considers most
  4. 4. 1. The web server sends the query to3. The search results are returned to the index servers. The content insidethe user in a fraction of a second. the index servers is similar to the index in the back of a book--it tells which pages contain the words that match any2. The query travels to the doc particular query termservers, which actually retrieve thestored documents. Snippets aregenerated to describe each searchresult.Copyright
  5. 5. crawlingtechnology is needed to gather the web documents and keep them up to date.Storage space must be used efficiently to store indices and, optionally, thedocuments themselves.indexing The indexing system must process hundreds of gigabytes of data efficiently. Queries must be handled quickly, at a rate of hundreds to thousands per second..Google is designed to scale well to extremely large data sets. It makesefficient use of storage space to store the index. Its data structures are optimized for fast and efficient access Further,we expect that the cost to index and store text or HTML will eventuallydecline relative to the amount that will be available This will result infavourable scaling properties for centralized systems like Google.
  6. 6. The Google search engine has two important features that help itproduce high precision results.First it makes use of the link structure of the Web to calculate aquality ranking for each web page. This rankingis called PageRank.Second Google utilizes link to improve search results.
  7. 7. PageRank: Bringing Order to the WebThe citation (link) graph of the web is an important resource that has largely goneunused in existing web search engines. they have created maps containing as many as 518 million of these hyperlinks Thesemaps allow rapid calculation of a web page’s "PageRank", anobjective measure of its citation importance that corresponds well with people’ssubjective idea of importance Because of this correspondence, PageRank is anexcellent way to prioritize the results of web keyword searches For most popularsubjects, a simple text matching search that is restricted to webpage titles performs admirably when PageRank prioritizes the results For the type offull text searches in the main Google system, PageRank also helpsa great deal.
  8. 8. Anchor TextThe text of links is treated in a special way in our search engine. Most searchengines associate the text of a link with the page that the link is on. In addition,we associate it with the page the link points to.This has several advantages. First, anchors often provide more accurate descriptions of web pages thanthe pages themselves. Second, anchors may exist for documents which cannot be indexed by atext-based search engine, such as images, programs, and databases. This makes itpossible to return webpages which have not actually been crawled. Note that pages that have not beencrawled can causeproblems, since they are never checked for validity before being returned to theuser. In this case, thesearch engine can even return a page that never actually existed, but hadhyperlinks pointing to it.However, it is possible to sort the results, so that this particular problem rarelyhappens.
  9. 9. Aside from PageRank and the use of anchor text, Google hasseveral other features.First- it has location information for all hits and so it makesextensive use of proximity in search.Second- Google keeps track of some visual presentation detailssuch as font size of words. Words in a larger or bolder font areweighted higher than other words.Third- full raw HTML of pages is available in a repository.
  10. 10. The Google Advanced Search is of course applicable totexts, terms, files and so on. In thatway is possible to do an advanced search in texts withfollowing terms:• Idioms• Format file• Domains• Books• Codes
  11. 11. Figura 1: Google Advanced Image Search
  12. 12. 1. Parse the query.2. Convert words into wordIDs.3. Seek to the start of the doclist in the short barrel for every word4. Scan through the doclists until there is a document that matches all the search terms.5. Compute the rank of that document for the query.6. If we are in the short barrels and at the end of any doclist, seek to the start of the doclist in the full barrel for every word and go to step 4.7. If we are not at the end of any doclist go to step 4. Sort the
  13. 13. What is a query? Its a request for information from a searchengine. A query consists of one or more words, numbers, or phrasesthat youhope you will find in the search results listings.To enter a query, type in descriptive words into Googles searchbox. You can use either the search box on Googles home page(shown above) or the search box that always appears at the top ofa Google results page .Now press the ENTER key or click on the "Google Search" button toview your search results, which include links to pages that matchyourquery along with relevant snippets (excerpts) with your searchterms in a boldface
  14. 14. Search within resultsYou can get the same results in one step fewer by simply specifying additional terms toyour previous query.On Internet Explorer and on some other browsers, you can double click on a term tohighlight it. Then type a new term or hit theDELETE key to remove the term. Triple click in the search box to highlight your entirequery. Enter a new query or hit the DELETE key toremove the old query.l Instead of searching for related topics with a single query, divide the query into severalparts. Looking for a job? By searching for tips oneach aspect, youll find more sites than by searching for sites that describe all the aspectsof a job search
  15. 15. Google Earth is very famous interactive application mapping program poweredby satellite andaerial imagery that covers the vast majority of the planet. Google Earth is generally considered to be remarkably accurate and extremely detailed. Many major cities in the planet have such detailed images that one canzoom in close enough to see vehicles and pedestrians clearly. Consequentlythere have been some concerns about national security implications in despite ofthe images hasbeen not updated constantly.Google has many others products through the Google Labs notreleased yet due it are still being tested for use by general public.One good differential on Google Search is regarding to logic engine based onBoolean Logiccreated by mathematician Britain George Boole. Therefore the Google engine allowsfinding words,texts and so on using logic values conditioned to:• The value must be true or false• The value must not be true and false at same time• If true, it is defined as 1 and if false it is defined as 0(zero
  16. 16. Now we came to Google Desktop (2) is desktop search softwaremade by Google for Mac OS X,Linux, and Microsoft Windows. The program allows text searches ofa users e-mails, computer files,music, photos, chats, Web pages viewed, and other "GoogleGadgets."Google Desktop have the following features: File indexing: After initially installing Google Desktop, the software completes an indexing of all the files in the computer And after the initial indexing is completed, the software continues to index files as needed. Users can start searching for files immediately after installing the program. After performing searches, results can also be returned in an Internet browser on the Google Desktop Home Page much like the results for Google Web searches.
  17. 17. • Sidebar: Screenshot of gadgets. Google Desktop running on Microsoft WindowsVista. Aprominent feature of Google Desktop is the Sidebar, which holds several commonGadgetsand resides off to one side of the desktop. The Sidebar is available with theMicrosoftWindows version of Google Desktop only. The Sidebar comes pre-installed with thefollowing gadgets: Email - a panel which lets one view ones Gmail messages. Scratch Pad - here one can store random notes; they are saved automatically Photos - displays a slideshow of photos from the "My Pictures" folder .News - shows the latest headlines from Google News, and how long ago they werewritten. The News panel is personalized depending on the type of news you read. Weather - shows the current weather for a location specified by the user. Web Clips - shows recent posts from RSS news feeds. Google Talk - If Google Talk is installed, double clicking the window title will dockit to ones sidebar
  18. 18. Quick Find: When searching in the sidebar, deskbar or floatingdeskbar, Google Desktopdisplays a "Quick Find" window. This window is filled with 6 (bydefault) of the most relevantresults from ones computer. These results update as one types sothat one can get to whatone wants on ones computer without having to open anotherbrowser window.
  19. 19. Deskbars: Deskbars are boxes which enable oneto type in a search query directly fromones desktop. Web results will open in a browserwindow and selected computer results willbe displayed in the "Quick Find" box (see above). ADeskbar can either be a fixed deskbar,which sits in ones Windows Taskbar, or a FloatingDeskbar, which one may positionanywhere one wants on ones desktop.
  20. 20. THANK YOU