Domain Name System also called as DNS is an Internet naming scheme. Computers or any other network devices are referred to by a set of numbers known as IP address. But it is very difficult to remember these IP addresses so they are given more meaning labels called hostnames which, when online, are also named URLs (Unifrom Resource Locators). As now there are millions of computers across the world, these names need to be systemized to avoid confusion. Therefore they are stored in hierarchical manner in machines known as DNS name servers. These DNS name servers are distributed all across the world. Every domain, company, organization, school, and other major establishments have atleast one DNS name server.
When you subscribe to any internet service provider or ISP, setting up your connection by using their DNS server is a part of their process. These name servers under ISP also possess cache memory with the help of which they can store the results of DNS queries for certain period of time, which enables any other computer to look for same URL fast. But for that, these ISPs are required to keep their DNS name server info fast, secure and reliable. However, most of the ISPs fail in one or more out of these criteria.
Here comes the role of public DNS services which are also almost free. Lot of companies are there such as OpenDNS, ScrubIt, dnsadvantage, etc which provide free usage of its name servers to any devices looking for DNS support. For setting up these servers, you just need to enter IP address of one or more of them. Google DNS is one strong competitor in this game. They claim to offer DNS service which is not only free but also faster, more secure and reliable as compared to others.
To test its credibility, various online tests have been conducted. A click to Wikipedia site measures the average speed at time 288ms, which is a little slower than 281 ms at which my ISP’s name servers clocked. For URLs which do not exist, Google DNS comes up with non-existent domain replies (NXDOMAIN), the familiar “Server not Found” error. These are some of the features that make Google DNS very different from other public DNS resolvers. According to Google, they are working against NXDOMAIN redirects as these are tactics of most of the public DNS servers to redirect NXDOMAIN errors to a website made by a company, with some links, which are full of annoying ads.
Sometimes things are not as they seem. According to Google DNS’ privacy page, they never keep user-specific information which includes full IP addresses of computers. But they keep statistics of general geo-locations, browsed websites, and other technical info, but this is also done by most web analysis tools. So it is just that Google DNS tells you more about how to use the Internet. But if they are claiming to be the best DNS server provider, then there is no harm to go for it.