If you use Google public DNS service all your client programs will perform DNS lookup via Google public DNS. Google Public DNS is a free, global Domain Name System (DNS) resolution service, that you can use as an alternative to your current DNS provider.
Google introduced public DNS, where users can point DNS server IP to Google public DNS IP. Which helps to surf the internet faster and secure. Google Public DNS service is similar to OpenDNS which helps to surf the web faster and secure. Configure your network settings to use the IP addresses 184.108.40.206 and 220.127.116.11 as your DNS servers (or)
The DNS protocol is an important part of the web's infrastructure, serving as the Internet's phone book: every time you visit a website, your computer performs a DNS lookup. Complex pages often require multiple DNS lookups before they start loading, so your computer may be performing hundreds of lookups a day.
Google Public DNS - A New Way To Browse Faster