
With "Caffeine", Google moved its back-end indexing system away from MapReduce and onto Bigtable, the company's distributed database platform. Google announced completion of "Caffeine" on June 8, 2010, claiming 50% fresher results due to continuous updating of its index.

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, as well as the launch of Wolfram Alpha, a new search engine based on "computational knowledge". The new architecture provided no visual differences in the user interface, but added significant speed improvements and a new "under-the-hood" indexing infrastructure. In August 2009, Google invited web developers to test a new search architecture, codenamed "Caffeine", and give their feedback. In December 2017, Google began rolling out the change, having already done so for multiple websites. The change was a response to the continued growth in mobile usage, and a push for web developers to adopt a mobile-friendly version of their websites. In October 2016, Gary Illyes, a webmaster trends analyst with Google, announced that the search engine would be making a separate, primary web index dedicated for mobile devices, with a secondary, less up-to-date index for desktop use. In 2012, Google changed its search indexing tools to demote sites that had been accused of piracy. ĭespite Google search's immense index, sources generally assume that Google is only indexing less than 5% of the total Internet, with the rest belonging to the deep web, inaccessible through its search tools. Users can also activate " SafeSearch", a filtering technology aimed at preventing explicit and pornographic content from appearing in search results. Additionally, Google indexes some file types, being able to show users PDFs, Word documents, Excel spreadsheets, PowerPoint presentations, certain Flash multimedia content, and plain text files. For websites that are currently down or otherwise not available, Google provides links to cached versions of the site, formed by the search engine's latest indexing of that page. Google indexes hundreds of terabytes of information from web pages.

As of mid-2016, Google's search engine has begun to rely on deep neural networks. Data about the frequency of use of search terms on Google can be openly inquired via Google Trends and have been shown to correlate with flu outbreaks and unemployment levels, and provide the information faster than traditional reporting methods and surveys. In 2012, Google introduced a Knowledge Graph semantic search feature.Īnalysis of the frequency of search terms may indicate economic, social and health trends. In 2011, Google introduced " Google Voice Search" to search for spoken, rather than typed, words. It was originally developed in 1996 by Larry Page, Sergey Brin, and Scott Hassan. The main purpose of Google Search is to search for text in publicly accessible documents offered by web servers, as opposed to other data, such as images or data contained in databases. Google Search also provides many different options for customized searches, using symbols to include, exclude, specify or require certain search behavior, and offers specialized interactive experiences, such as flight status and package tracking, weather forecasts, currency, unit, and time conversions, word definitions, and more. The order of search results returned by Google is based, in part, on a priority rank system called " PageRank".

Additionally, it is the most searched and used search engine in the entire world.

It is the most-visited website in the world. Handling more than 3.5 billion searches per day, it has a 92% share of the global search engine market. Google Search (also known simply as Google or ) is a search engine provided and operated by Google.
