Web search engine launched on June 1, 2009. On July 29, 2009, Yahoo! and Microsoft finalized a deal in which Yahoo! Search would be powered by Microsoft Bing technology. A search engine maintains the following processes in near real time: Web search engines get their information by web crawling from site to site. The "spider" checks for the standard filename "robots.txt", addressed to it, before sending certain information back to be indexed depending on many factors, such as the titles, page content, JavaScript, Cascading Style Sheets (CSS), headings, as evidenced by the standard HTML markup of the informational content, or its metadata in
Search engine privacy DuckDuckGo. There have been several well publicized breaches of search engine user privacy that occurred with companies like AOL and Yahoo. For individuals interested in preserving their privacy from search engines, there are many routes available to them, such as using an anonymity software like Tor that attempts to separate the user's location and information from their search. Search engines generally have privacy policies in order to inform users about what data of theirs they may be collecting and what purposes it may be used for. While these policies may be an attempt at transparency by search engines, many people