Google Search

Google Search (or Google Web Search) is a web search engine owned by Google Inc. Google Search is the most-used search engine on the World Wide Web, handling more than three billion searches each day.

The order of search on Google's search-results pages is based, in part, on a priority rank called a "PageRank". Google Search provides many options for customized search, using Boolean operators such as: exclusion ("-xx"), alternatives ("xx OR yy"), and wildcards ("x * x").

The main purpose of Google Search is to hunt for text in publicly accessible documents offered by web servers, as opposed to other data, such as with Google Image Search. Google Search was originally developed by Larry Page and Sergey Brin in 1997. Google Search provides at least 22 special features beyond the original word-search capability. These include synonyms, weather forecasts, time zones, stock quotes, maps, earthquake data, movie showtimes, airports, home listings, and sports scores. There are special features for dates, including ranges, prices, temperatures, money/unit conversions, calculations, package tracking, patents, area codes, and language translation of displayed pages. In June 2011, Google introduced "Google Voice Search" and "Search by Image" features for allowing the users to search words by speaking and by giving images. In May 2012, Google introduced a new Knowledge Graph semantic search feature to customers in the U.S.

The frequency of use of many search terms has reached such a volume that they may indicate broader economic, social and health trends. Data about the frequency of use of search terms on Google have been shown to correlate with flu outbreaks and unemployment levels and provide the information faster than traditional reporting methods and government surveys.

Major competitors of Google are Baidu and Soso.com in China; Naver.com and Daum Communications in South Korea; Yandex in Russia; Seznam.cz in Czech Republic; Yahoo! in Japan, Taiwan and the United States, and Bing.

PageRank
Google's rise to success was in large part due to a patented algorithm called PageRank that helps rank web pages that match a given search string. When Google was a Stanford research project, it was nicknamed BackRub because the technology checks backlinks to determine a site's importance. 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. The PageRank algorithm instead analyzes human-generated links assuming that web pages linked from many important pages are themselves likely to be important. The algorithm computes a recursive score for pages, based on the weighted sum of the PageRanks of the pages linking to them. PageRank is thought to correlate well with human concepts of importance. In addition to PageRank, Google, over the years, has added many other secret criteria for determining the ranking of pages on result lists, reported to be over 250 different indicators, the specifics of which are kept secret to keep spammers at bay and help Google maintain an edge over its competitors globally.

In 2013 the European Commission found that Google Search favored Google's own products, instead of offering consumers the best result for their needs.

Search products
The exact percentage of the total of web pages that Google indexes is not known, as it is very difficult to accurately calculate. Google presents a two-line summary and also a preview of each search result, which includes a link to a cached (stored), usually older version of the page.

Google's cache link in its search results provides a way of retrieving information from websites that have recently gone down and a way of retrieving data more quickly than by clicking the direct link. This feature is still available, but many users are not aware of this because it has been moved to the previews of the search results presented next to these.

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 so on. 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. The ability to specify the number of results is available only if "Instant Search" is not enabled. If "Instant Search" is enabled, only 10 results are displayed, regardless of this setting.

In 2012, Google changed its rankings to demote sites that had been accused of piracy, excepting the Google-owned YouTube site.

Non-indexable data
Despite its immense index, there is also a considerable amount of data available in online databases which are accessible by means of queries but not by links. This so-called invisible or deep Web is minimally covered by Google and other search engines. The deep Web contains library catalogs, official legislative documents of governments, phone books, and other content which is dynamically prepared to respond to a query.

Google optimization
Because 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 increase 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 to draw more searchers to their client's sites. Search engine optimization encompasses both "on page" factors (like body copy, title elements, H1 heading elements and image alt attribute values) 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 element and the body copy (note: the higher up in the page, presumably 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. Google has published guidelines for website owners who would like to raise their rankings when using legitimate optimization consultants. It has been hypothesized, and, allegedly, is the opinion of the owner of one business about which there have been numerous complaints, that negative publicity, for example, numerous consumer complaints, may serve as well to elevate page rank on Google Search as favorable comments. The particular problem addressed in The New York Times article, which involved DecorMyEyes, was addressed shortly thereafter by an undisclosed fix in the Google algorithm. According to Google, it was not the frequently published consumer complaints about DecorMyEyes which resulted in the high ranking but mentions on news websites of events which affected the firm such as legal actions against it. Google Webmaster Tools helps to check for websites that use duplicate or copyright content.

Functionality
Google search consists of a series of localized websites. The largest of those, the google.com site, is the top most-visited website in the world. Some of its features include a definition link for most searches including dictionary words, the number of results you got on your search, links to other searches (e.g. for words that Google believes to be misspelled, it provides a link to the search results using its proposed spelling), and many more.

Search syntax
Google's search engine normally accepts queries as a simple text, and breaks up the user's text into a sequence of search terms, which will usually be words that are to occur in the results, but one can also use Boolean operators, such as: quotations marks (") for a phrase, a prefix such as "+", "-" for qualified terms (no longer valid, the '+' was removed from Google on October 19, 2011), or one of several advanced operators, such as "site:". The webpages of "Google Search Basics" describe each of these additional queries and options (see below: Search options). Google's Advanced Search web form gives several additional fields which may be used to qualify searches by such criteria as date of first retrieval.

Query expansion
Google applies query expansion to the submitted search query, transforming it into the query that will actually be used to retrieve results. As with page ranking, the exact details of the algorithm Google uses are deliberately obscure, but certainly the following transformations are among those that occur:
 * Term reordering: in information retrieval this is a standard technique to reduce the work involved in retrieving results. This transformation is invisible to the user, since the results ordering uses the original query order to determine relevance.
 * Stemming is used to increase search quality by keeping small syntactic variants of search terms.
 * There is a limited facility to fix possible misspellings in queries.

"I'm Feeling Lucky"
Google's homepage includes a button labeled "I'm Feeling Lucky". When a user types in a search and clicks on the button the user will be taken directly to the first search result, bypassing the search engine results page. The idea is that if a user is "feeling lucky", the search engine will return the perfect match the first time without having to page through the search results. However, with the introduction of Google Instant, it is not possible to use the button properly unless the Google Instant function is switched off. According to a study by Tom Chavez of "Rapt", this feature costs Google $110 million a year as 1% of all searches use this feature and bypass all advertising.

Google Chrome and Mozilla Firefox used Lucky Search as the default search string when the user entered a query in the location bar. This functionality was deprecated in later versions, but can be brought back in Mozilla Firefox by setting the keyword.URL string to http://www.google.com/search?ie=UTF-8&oe=UTF-8&sourceid=navclient&btnI=1&q= on the page about:config.

Rich Snippets
On May 12, 2009, Google announced that they would be parsing the hCard, hReview, and hProduct microformats and using them to populate search result pages with what they called "Rich Snippets". See also Google Searchology.

Special Features
Besides the main search-engine feature of searching for text, Google Search has more than 22 "special features" (activated by entering any of dozens of trigger words) when searching:
 * weather – The weather conditions, temperature, wind, humidity, and forecast, for many cities, can be viewed by typing "weather" along with a city for larger cities or city and state, U.S. zip code, or city and country for smaller cities (such as: weather Lawrence, Kansas; weather Paris; weather Bremen, Germany).
 * stock quotes – The market data for a specific company or fund can be viewed, by typing the ticker symbol (or include "stock"), such as: CSCO; MSFT; IBM stock; F stock (lists Ford Motor Co.); or AIVSX (fund). Results show inter-day changes, or 5-year graph, etc. This does not work for many stock names which are one letter long, such as Macy's (M), or are common words, such as Diamond Offshore (DO) or Majesco (COOL).
 * time – The current time in many cities (worldwide), can be viewed by typing "time" and the name of the city (such as: time Cairo; time Pratt, KS).
 * sports scores – The scores and schedules, for sports teams, can be displayed by typing the team name or league name into the search box.
 * unit conversion – Measurements can be converted, by entering each phrase, such as: 10.5 cm in inches; or 90 km in miles
 * currency conversion – A money or currency converter can be selected, by typing the names or currency codes (listed by ISO 4217): 6789 Euro in USD; 150 GBP in USD; 5000 Yen in USD; 5000 Yuan in lira (the U.S. dollar can be USD or "US$" or "$", while Canadian is CAD, etc.).
 * calculator – Calculation results can be determined, as calculated live, by entering a formula in numbers or words, such as: 6*77 +pi +sqrt(e^3)/888 plus 0.45. The user is given the option to search for the formula, after calculation. The calculator also uses the unit and currency conversion functions to allow unit-aware calculations. For example, "(3 EUR/liter) / (40 miles/gallon) in USD / mile" calculates the dollar cost per mile for a 40 mpg car with gas costing 3 euros a liter. The caret "^" raises a number to an exponent power, and percentages are allowed ("40% of 300"). Following the convention used in discrete mathematics, Google's calculator evaluates 0^0 to 1. The calculator also can calculate digital storage arithmetic (the calculation of bytes). For example, putting in 400MB + 489MB + 1.5GB yields the result 2425MB, or 2.37GB.  This is useful since bytes are binary (power of 2), and not decimal as regular numbers are (power of 10).
 * numeric ranges – A set of numbers can be matched by using a double-dot between range numbers (70..73 or 90..100) to match any positive number in the range, inclusive. Negative numbers are treated as using exclusion-dash to not match the number.
 * dictionary lookup – A definition for a word or phrase can be found, by entering "define" followed by a colon and the word(s) to look up (such as, "define:philosophy")
 * maps – Some related maps can be displayed, by typing in the name or U.S. ZIP code of a location and the word "map" (such as: New York map; Kansas map; or Paris map).
 * movie showtimes – Reviews or film showtimes can be listed for any movies playing nearby, by typing "movies" or the name of any current film into the search box. If a specific location was saved on a previous search, the top search result will display showtimes for nearby theaters for that movie.
 * public data – Trends for population (or unemployment rates) can be found for U.S. states and counties, by typing "population" or "unemployment rate" followed by a state or county name.
 * real estate and housing – Home listings in a given area can be displayed, using the trigger words "housing", "home", or "real estate" followed by the name of a city or U.S. zip code.
 * travel data/airports – The flight status for arriving or departing U.S. flights can be displayed, by typing in the name of the airline and the flight number into the search box (such as: American airlines 18). Delays at a specific airport can also be viewed (by typing the name of the city or three-letter airport code plus word "airport").
 * package tracking – Package mail can be tracked by typing the tracking number of a Royal Mail, UPS, FedEx or USPS package directly into the search box. Results will include quick links to track the status of each shipment.
 * patent numbers – U.S. patents can be searched by entering the word "patent" followed by the patent number into the search box (such as: Patent 5123123).
 * area code – The geographical location (for any U.S. telephone area code) can be displayed by typing a three-digit area code (such as: 650).
 * synonym search – A search can match words similar to those specified, by placing the tilde sign (~) immediately in front of a search term, such as: ~fast food.
 * Six degrees of Kevin Bacon - A search to find the shortest path between an arbitrary actor and veteran Hollywood character actor Kevin Bacon. Simply search using 'bacon number actorname'.
 * Google Goggles - using the google goggles app on your smartphone you can take a photograph of anything and get quick results for your search. If you wish to pursue more detailed search results you can click the "full results" tab and get a full blown google search of the object you photographed.

Search options
The webpages maintained by the Google Help Center have text describing more than 15 various search options. The Google operator
 * OR – Search for either one, such as "price high OR low" searches for "price" with "high" or "low" (paramvee).
 * "-" – Search while excluding a word, such as "apple -tree" searches where word "tree" is not used.
 * "+" – (Removed on October 19, 2011). Force inclusion of a word, such as "Name +of +the Game" to require the words "of" & "the" to appear on a matching page.
 * "*" – Wildcard operator to match any words between other specific words.

Some of the query options are as follows:
 * define: – The query prefix "define:" will provide a definition of the words listed after it.
 * stocks: – After "stocks:" the query terms are treated as stock ticker symbols for lookup.
 * site: – Restrict the results to those websites in the given domain, such as, site:www.acmeacme.com. The option "site:com" will search all domain URLs named with ".com" (no space after "site:").
 * intext: – Prefix to search in a webpage text, such as "intext:google search" will list pages with word "google" in the text of the page, and word "search" anywhere (no space after "intext:").
 * allintitle: – Only the page titles are searched (not the remaining text on each webpage).
 * intitle: – Prefix to search in a webpage title, such as "intitle:google search" will list pages with word "google" in title, and word "search" anywhere (no space after "intitle:").
 * allinurl: – Only the page URL address lines are searched (not the text inside each webpage).
 * inurl: – Prefix for each word to be found in the URL; others words are matched anywhere, such as "inurl:acme search" matches "acme" in a URL, but matches "search" anywhere (no space after "inurl:").

The page-display options (or query types) are:
 * cache: – Highlights the search-words within the cached document, such as "cache:www.google.com xxx" shows cached content with word "xxx" highlighted.
 * link: – The prefix "link:" will list webpages that have links to the specified webpage, such as "link:www.google.com" lists webpages linking to the Google homepage.
 * related: – The prefix "related:" will list webpages that are "similar" to a specified web page.
 * info: – The prefix "info:" will display some background information about one specified webpage, such as, info:www.google.com. Typically, the info is the first text (160 bytes, about 23 words) contained in the page, displayed in the style of a results entry (for just the 1 page as matching the search).
 * filetype: – results will only show files of the desired type (ex filetype:pdf will return pdf files)

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." sometimes followed by a CAPTCHA prompt.

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. Google says the message is triggered only by high volumes of requests from a single IP address, however the use of the "allintext" operator a few times in a period of minutes has the same effect. Google apparently uses the Google cookie as part of its determination of refusing service.

In June 2009, after the death of pop superstar Michael Jackson, this message appeared to many internet users who were searching Google for news stories related to the singer, and was assumed by Google to be a DDoS attack, although many queries were submitted by legitimate searchers.

January 2009 malware bug


Google flags search results with the message "This site may harm your computer" if the site is known to install malicious software in the background or otherwise surreptitiously. Google does this to protect users against visiting sites that could harm their computers. For approximately 40 minutes on January 31, 2009, all search results were mistakenly classified as malware and could therefore not be clicked; instead a warning message was displayed and the user was required to enter the requested URL manually. The bug was caused by human error. The URL of "/" (which expands to all URLs) was mistakenly added to the malware patterns file.

Google Doodles
On certain occasions, the logo on Google's webpage will change to a special version, known as a "Google Doodle". This is a picture, drawing, or animation that includes the logo. It is usually done for a special event or day although not all of them are well known. Clicking on the Doodle links to a string of Google search results about the topic. The first was a reference to the Burning Man Festival in 1998, and others have been produced for the birthdays of notable people like Albert Einstein, historical events like the interlocking Lego block's 50th anniversary and holidays like Valentine's Day. Some Google Doodles have interactivity beyond a simple search, such as the famous "Google Pacman" version that appeared on May 21, 2010.

Google Caffeine
In August 2009, Google announced the rollout of a new search architecture, codenamed "Caffeine". The new architecture was designed to return results faster and to better deal with rapidly updated information from services including Facebook and Twitter. Google developers noted that most users would notice little immediate change, but invited developers to test the new search in its sandbox. Differences noted for their impact upon search engine optimization included heavier keyword weighting and the importance of the domain's age. The move was interpreted in some quarters as a response to Microsoft's recent release of an upgraded version of its own search service, renamed Bing. Google announced completion of Caffeine on June 8, 2010, claiming 50% fresher results due to continuous updating of its index. With Caffeine, Google moved its back-end indexing system away from MapReduce and onto BigTable, the company's distributed database platform. Caffeine is also based on Colossus, or GFS2, an overhaul of the GFS distributed file system.

Conversational search and Hummingbird update
During the Google I/O conference in May 2013, Google's Amit Singhal presented on the future of search, explaining that a search engine's three primary functions will need to evolve and that search will need to: 1. Answer, 2. Converse, and 3. Anticipate. As part of his keynote talk, Singhal stated, "A computer you can talk to? And it will answer everything you ask it? Little did I know, I would grow up to become the person responsible for building my dream for the entire world." Conversational search technology was then featured and Singhal introduced the term "hot-wording" to describe search without the need for an interface, whereby the user simply prompts the Google search engine by stating, "OK Google." The I/O audience was then shown a demonstration in which a user asked a question and the search engine answered back in "conversation," in addition to the presentation of results for the query.

The conversational search function was incorporated into the latest version of the Chrome browser during the week beginning May 20, 2013. The "OK Google" search prompt was not included into the upgrade and users are required to click on a microphone icon that appears on the right-hand side of the search box. Google displays its answer to the user's question in the form of "cards" at the top of the search results while the information is conveyed verbally—according to one search engine writer, Google continues to work through the feature's bugs.

The "Hummingbird" update was announced as part of Google's 15-year anniversary and a Guardian technology journalist described it as "the biggest change to the inner workings of the world's most popular search engine since Google's "Caffeine" update in 2010." The update was progressively introduced over the month prior to the announcement and will benefit more modern forms of search, whereby users ask Google a question rather than entering keywords into the search box.

Privacy
Searches made by search engines, including Google, leave traces, raising concerns about privacy but sometimes facilitating the administration of justice; murderers have been detected and convicted as a result of incriminating searches they made such as "tips with killing with a baseball bat".

A search can be traced in several ways. When using a search engine through a browser program on a computer, search terms and other information will usually be stored on the computer by default, unless steps are taken to erase them. An Internet Service Provider may store records which relate search terms to an IP address and a time. The search engine provider (e.g., Google) may keep logs with the same information. Whether such logs are kept, and access to them by law enforcement agencies, is subject to legislation and working practices; the law may mandate, prohibit, or say nothing about logging of various types of information.

The technically knowledgeable and forewarned user can avoid leaving traces.

Encrypted Search
In May 2010 Google rolled out SSL-encrypted web search. The encrypted search can be accessed at

FTC Fines
In 2012, the Federal Trade Commission fined Google $22.5 million for violating their pledge not to violate the privacy of users of the Apple Safari (web browser). The FTC was also continuing to investigate if Google's favoring of their own services in their search results violated antitrust regulations.

Instant Search


Google Instant, a feature that displays suggested results while the user types, was introduced in the United States on September 8, 2010. In concert with the Google Instant launch, Google disabled the ability of users to choose to see more than 10 search results per page. At the time of the announcement, Google expected Instant to save users 2 to 5 seconds in every search, collectively about 11 million seconds per hour. Search engine marketing experts speculate that Google Instant will have a great impact on local and paid search. To celebrate the launch of Google Instant, a "Google Doodle" was posted on the home page. In the interactive doodle, users were able to roll their cursor over a series of colored dots that made up the logo; when the cursor touched a group of dots, the dots would seemingly go up into the air, via 3D effects.

Instant Search can be disabled via Google's "preferences" menu, but autocomplete-style search suggestions now cannot be disabled. Google confirms that this is intentional.

The publication 2600: The Hacker Quarterly has compiled a list of words that are restricted by Google Instant. These are terms the web giant's new instant search feature will not search. Most terms are often vulgar and derogatory in nature, but some apparently irrelevant searches including "Myleak" are removed.

In September 2012 multiple sources reported that Google had removed bisexual from the list of blacklisted terms for Instant Search. However, as of late 2013 the word bisexual still does not autocomplete and LGBT activists renewed efforts to have it whitelisted.

Redesign
In late June 2011, Google introduced a new look to the Google home page in order to boost the use of the Google+ social tools.

One of the major changes was replacing the classic navigation bar with a black one. Google's digital creative director Chris Wiggins explains: "We're working on a project to bring you a new and improved Google experience, and over the next few months, you'll continue to see more updates to our look and feel." The new navigation bar has been negatively received by a vocal minority.

In November 2013, Google started testing yellow labels for advertisements displayed in search results, to improve user experience. The new labels, highlighted in yellow color, and aligned to the left of each sponsored link help users clearly differentiate between organic and sponsored results.

International
Google is available in many languages and has been localized completely or partly for many countries.

The interface has also been made available in some languages for humorous purpose:


 * Bork, bork, bork!
 * Elmer Fudd
 * Klingon
 * Leetspeak
 * Pig Latin
 * Pirate

In addition to the main URL Google.com, Google Inc. owns 160 domain names for each of the countries/regions in which it has been localized.

Search 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 2012, Google has indexed over 30 trillion web pages, and received 100 billion queries per month. It also caches much of the content that it indexes. Google operates other tools and services including Google News, Google Shopping, Google Maps, Google Co-op, Google Earth, Google Docs, Picasa, Panoramio, YouTube, Google Translate, Google Blog Search 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 includes search features; Google Browser Sync does not offer any search facilities, although it aims to organize your browsing time.

Also Google starts many new beta products, like Google Social Search or Google Image Swirl.

Energy consumption
Google claims that a search query requires altogether about 1 kJ or 0.0003 kW·h, which is enough to raise the temperature of one liter of water by 0.24 °C.