As Wikipedia explains,
The Domain Name System (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities. Most prominently, it translates easily memorised domain names to the numerical IP addresses needed for the purpose of locating computer services and devices worldwide. By providing a worldwide, distributed keyword-based redirection service, the Domain Name System is an essential component of the functionality of the Internet.
Google’s Public DNS will speed up your computer’s internet connection performance with faster speed for domain name lookup.
It is the highest quality tool for any web developer, designer, IT engineer or even a typical internet user who uses his internet daily.
It will provide security & speed through more excellent browsing performance.
Navigate to the below URL:
Link 01: https://developers.google.com/speed/public-dns/
Link 02: https://developers.google.com/speed/public-dns/docs/using
Now Copy the Google Public DNS Server IP Addresses given on the page & paste them into your current network settings as per the below steps.
Go to System Preferences in Dock > Network > Wi-Fi / Ethernet (whatever your current Internet network is) > Advanced… > DNS > Add your copied DNS server IP addresses copied from the Google Public DNS page > Press OK and then Apply, and you are done.
It will look something like this,
Hope it helps,
Thanks & Regards
Mandar Apte