Google Search Algorithm
Google Search or Google Web Search is a web search engine owned by Google Inc. and is the most-used search engine on the Web.Google receives several hundred million queries each day through its various services. The main purpose of Google Search is to hunt for text in webpages, 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.
The order of search results 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”), inclusion (“+xx”), alternatives (“xx OR yy”), and wildcard (“x * x”).
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 200 different indicators. The specifics of which are kept secret to keep spammers at bay and facilitate Google maintain an edge over its competitors globally.
The exact percentage of the total of web pages that Google indexes is not known, as it is very difficult to accurately calculate. 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.
ince 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 web design company“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.