Google Search

From Wikipedia, the free encyclopedia

Google, a search engine owned by Google, Inc is the most used search engine on the web. Google receives several hundred million queries each day through its various services.

Contents
1 The search engine
1.1 PageRank
1.2 Search results
1.3 Non-web sources of data
1.4 Google optimization
1.5 Uses of Google
1.6 Google dance
1.7 Googlability
2 Functionality
2.1 Search engine features
2.2 Error messages
3 International
3.1 Languages
3.2 Domain names
3.2.1 Cybersquatting
4 Search products
5 See also
6 References
7 Further reading
8 External links
The search engine

PageRank
Main article: PageRank
Google's algorithm uses a patented system called PageRank to help rank web pages that match a given search string. The PageRank algorithm computes a recursive score for web pages, based on the weighted sum of the PageRanks of the pages linking to them. The PageRank derives from human-generated links, and correlates well with human concepts of importance.
The exact percentage of the total of web pages that Google indexes are not known, as it is very hard to actually calculate it. Previous keyword-based methods of ranking search results, used by many search engines that were once more popular than Google would rank pages by how often the search terms occurred in the page, or how strongly associated the search terms were within each resulting page. In addition to PageRank, Google also uses other secret criteria for determining the ranking of pages on result lists, reported to number over 150.[2]

Search results
Google not only indexes and caches web pages but also takes "snapshots" of other file types, which include PDF, Word documents, Excel spreadsheets, Flash SWF, plain text files and much more.[3] Except in the case of text and SWF files, the cached version is a conversion to (X)HTML, allowing those without the corresponding viewer application to read the file.
Users can customize the search engine, by setting a default language, using the "SafeSearch" filtering technology and set the number of results shown on each page. Google has been criticized for placing long-term cookies on users' machines to store these preferences, a tactic which also enables them to track a user's search terms and retain the data for more than a year. For any query, up to the first 1000 results can be shown with a maximum of 100 displayed per page.

Non-web sources of data
Despite its immense index, there is also a considerable amount of data in databases, which are accessible from websites by means of queries but not by links. This so-called deep web is minimally covered by Google and contains, for example, catalogs of libraries, official legislative documents of governments, phone books, and more.

Google optimization
Main article: Search Engine Optimization
Since Google is the most popular search engine, many webmasters have become eager to influence their website's Google rankings. An industry of consultants has arisen to help websites raise their rankings on Google and on other search engines. This field, called search engine optimization, attempts to discern patterns in search engine listings, and then develop a methodology for improving rankings.
As Google's algorithms and results have gained the trust of web users, commercial websites will profit from subverting these results by artificially inflating their rankings. Some search engine optimization firms have attempted to inflate specific Google rankings by various artifices, and thereby draw more searchers to their client's sites. One of Google's main challenges has been to weaken some of these attempts by reducing the ranking of sites known to use them.
Search engine optimization encompasses both "on page" factors (like body copy, title tags, H1 heading tags and image alt attributes) and Off Page Optimization factors (like anchor text and PageRank). The general idea is to affect Google's relevance algorithm by incorporating the keywords being targeted in various places "on page", in particular the title tag and the body copy (note: the higher up in the page, the better its keyword prominence and thus the ranking). Too many occurrences of the keyword, however, cause the page to look suspect to Google's spam checking algorithms.
The Google webmaster guidelines were published for website owners who would like to raise their rankings when using legitimate optimization consultants.[4]

Uses of Google
A corollary use of Google — and other Internet search engines — is that it can help translators to determine the most common way of expressing ideas in the English language (and other languages). This is generally done by doing a 'count' of different variants, thereby establishing which expression is more common. While this approach requires careful judgment, it does improve the ability of non-native translators to use more idiomatically correct English expressions.

Google dance
Google dance refers to the period of time when Google indices are tuned. This will often cause both a fluctuation in index size as well a significant change in a web site's search result position.
"Google Dance" also refers to the annual party at the Googleplex during the Search Engine Strategies San Jose conferences.

Googlability
Googlability is the degree to which an individual index can be referenced.

Functionality

The Google search engine has many Intuitive Features making it more functional, that could have played a small role in making it as popular as it is today. Google is along with Wikipedia one of the Top Ten most visited websites today[citation needed] (2008). Some of the features include a definition link for most searches including dictionary words, a list of how many results you got on your search, links to other searches like for instance you mispelled something it gives you a link to the search results for if you had typed in the correct search, and many more. It is unknown whether its' functionality, speed, or luck it was brought it to the status it it is today(2008).

Search engine features
Besides the main search engine feature of searching for text, the search engine can be used as a calculator, currency converter, dictionary and many other useful tools. The largest number the Google calculator can compute (based on studies conducted at the University of Bath in January 2008) is 1.07257416E308.

Error messages
Some searches will give a 403 Forbidden error with the text
"We're sorry... ... but your query looks similar to automated requests from a computer virus or spyware application. To protect our users, we can't process your request right now. We'll restore your access as quickly as possible, so try again soon. In the meantime, if you suspect that your computer or network has been infected, you might want to run a virus checker or spyware remover to make sure that your systems are free of viruses and other spurious software. We apologize for the inconvenience, and hope we'll see you again on Google."
followed by a CAPTCHA prompt.[5]
The screen was first reported in 2005, and was a response to the heavy use of Google by search engine optimization companies to check on ranks of sites they were optimizing. The message may also be triggered by high volumes of different searches from a single IP address. The block is removed after a day.[citation needed]

International
Google is available in many languages and has been localized for many countries[6].

Languages
Afrikaans
Albanian
Amharic
Arabic
Armenian
Azerbaijani
Basque
Belarusian
Bengali
Bihari
Bosnian
Breton
Bulgarian
Cambodian (Khmer)
Catalan
Chinese (Simplified)
Chinese (Traditional)
Corsican
Croatian
Czech
Danish
Dutch
English
Esperanto
Estonian
Faroese
Filipino
Finnish
French
Frisian (West)
Galician
Georgian
German
Greek
Guarani
Gujarati
Hebrew
Hindi
Hungarian
Icelandic
Indonesian
Interlingua
Irish
Italian
Japanese
Javanese
Kannada
Kazakh
Korean
Kurdish
Kyrgyz
Laothian
Latin
Latvian
Lingala
Lithuanian
Macedonian
Malay
Malayalam
Maltese
Marathi
Moldavian (Romanian)
Mongolian
Nepali
Norwegian
Norwegian (Nynorsk)
Occitan
Oriya
Pashto
Persian
Polish
Portuguese (Brazil)
Portuguese (Portugal)
Punjabi
Quechua
Romanian
Romansh
Russian
Scots Gaelic
Serbian
Serbo-Croatian
Sesotho
Shona
Sindhi
Sinhalese
Slovak
Slovenian
Somali
Spanish
Sundanese
Swahili
Swedish
Tajik
Tamil
Tatar
Telugu
Thai
Tigrinya
Tonga
Turkish
Turkmen
Twi
Uighur
Ukrainian
Urdu
Uzbek
Vietnamese
Welsh
Xhosa
Yiddish
Yoruba
Zulu
The interface has also been made available in constructed languages for humorous purpose:
Klingon
Bork, bork, bork!
Elmer Fudd
Hacker (actually leetspeak)
Pig Latin

Domain names
In addition to the main URL Google.com, Google owns 160 domain names for each of the countries/regions in which is has been localized.[6] As Google is an American company, the main domain name can be considered as the U.S. one though the gTLD .com can be used by any company in the world (not only those from the United States). Google.us does exist but is only a redirection to google.com because dot-US is by far less common than dotcom in the United States. An example is Google.ca
List of domain names[show]

Cybersquatting
Some domain names unregistered by Google are currently squatted:
Google.by (Belarus), the correct URL is google.com.by
Google.cm (Cameroon), common mis-typing of google.com (there is no localized version for Cameroon)

Search products
Main article: List of Google products
In addition to its tool for searching webpages, Google also provides services for searching images, Usenet newsgroups, news websites, videos, searching by locality, maps, and items for sale online. In 2006, Google has indexed over 25 billion web pages, 1.3 billion images, and over one billion Usenet messages.[citation needed] It also caches much of the content that it indexes. Google operates other tools and services including Google News, Google Suggest, Google Product Search, Google Maps, Google Co-op and Google Desktop Search.
There are also products available from Google that are not directly search-related. Gmail, for example, is a webmail application, but still include search features; Google Browser Sync does not offer any search facilities, although it aims to organize your browsing time.