Key difference: Google and DuckDuckGo are both web search engines. The difference between the two search engines is based on the user interface and algorithms, which the corporations use to find the information from internet.  

Google Search is a web search engine owned by Google Inc. it is the most-used search engine on the World Wide Web, handling more than three billion searches each day. Google Inc. is an American multinational internet corporation; it is based in Mountain View, California. Larry Page and Sergey Brin founded the company in September 1998.

The main purpose of Google Search Engine is to hunt for text in publicly accessible documents offered by web servers. The search results is based on a priority rank called a ‘PageRank’; it also provides options for customized search. It features the original word-search capability, along with 22 other special features which include synonyms, weather forecasts, time zones, home listings, sports scores, and language translation of displayed pages, etc. In 2011, Google introduced ‘Google Voice Search’ and ‘Search by Image’ features, allowing the users to search words by speaking and by giving images.

Google search consists of a series of localized websites. It applies query expansion to the submitted search query, transforming it into the query that will actually be used to retrieve results. Also, Google's homepage includes a button labeled "I'm Feeling Lucky". 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. It has a malware bug, which flags the search results if the site is known to install malicious software in the background.

However, there are concerns based on the web search privacy. They were fined $22.5 million for violating their pledge not to violate the privacy of users and are still under investigation. Google is available in many languages and has been localized completely or partly for many countries. 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.

According to industry estimates, Google currently runs over one million servers in data centers around the world and processes over one billion search requests, also about twenty-four petabytes of user data is generated every day. Google first rose to fame with its web search engine, eventually expanding into email, an office suite, social networking, applications for web browsing, organizing and editing photos, and instant messaging, all via various acquisitions, and partnerships. Under its banner, Google also has Youtube, Blogger, FeedBurner, Gmail, Chrome, Google+, Orkut, Google Adwords, Google Adsense, DoubleClick, Meebo, Google Apps, Google Maps, and various more.

DuckDuckGo is a general purpose search engine with a focus on user experience, and is founded by the company CEO, Gabriel Weinberg. The company is based in Paoli, Pennsylvania, United States, and has 20 employees.

DuckDuckGo search engine emphasizes on protecting the user’s privacy and avoiding the ‘filter bubble’ of personalized search results. It distinguishes itself from other search engines by not profiling its users and showing all users the same search results for a given search term. It also emphasizes on getting information from the best sources rather than the most sources, by generating its search results from key crowd-sourced sites such as Wikipedia, Yandex, Yahoo!, Bing and WolframAlpha.

DuckDuckGo is based on zero-click information, category pages, ambiguous keyword detection, simpler links, topic detection and less spam. It often displays information based on the more traditional results. This information is called as ‘Zero-click Info’ and includes topic summaries, images and related topics, and often answers the search queries directly. Other information that DuckDuckGo provides on-site are ‘Category Pages’, which are group topics based on searches and enable you to discover useful topics related to the search.

It uses a proprietary technology called semantic topic detection, which allows the site to detect topics within the given search queries. It relates and targets the particular topic and adjusts the search to get the particular results. Also, it tries to strip out all the ‘garbage’ from the usual search result pages, with the primary goal of getting the information faster and with less effort. That is, DuckDuckGo has much less clutter, much less ads, and much less spam. As a result, it can often display much simpler links.

In terms of spam, DuckDuckGo takes both a bottom-up and top-down approach. From bottom-up, it regularly searches the web by identifying spasm and parked domains, and then omits them from the results. Similarly, from the top-down, DuckDuckGo draws on human police for spam. By using links from them, in the search results the site simply displays and contains less spam from the internet.

Finally, by making these changes, DuckDuckGo in general provides a much simpler interface, thus making the searches a more pleasant experience. In particular, it uses bigger text, bigger click able areas and more white space, both increasing usability and easier interface.

Comparison between Google and DuckDuckGo:

Image Courtesy: michaelzimmer.org, geeksaber.com