You might have heard of the terms DNS, DNS Server and changing DNS Server settings, but do you know what they are? May be you have changed your DNS Server settings for some reason, but do you really know what you are doing? For those of you that answer these questions with a “NO” here is a brief and simple explanation.
What is DNS?
DNS (Domain Name System) is a standard technology for managing the names of Web sites and other Internet domains. DNS is like a phone book, that matches human-readable names (domain names ) to numbers (IPs). DNS translates domain names into IP addresses.
What is a DNS Server?
DNS System is composed of DNS Servers that do this translation. They match domain names like big.info to their associated IP addresses. When you type big.info into your web browser’s address bar, your computer contacts your current DNS server and asks for the IP address that is associated with big.info. Your computer then sends the request to that IP address and displays the content of big.info in your web browser.
Why Change DNS Server?
When you change the DNS servers that your router/modem uses, you're changing the servers (usually assigned by your ISP) that you use to convert domain names to IP addresses. In other words, you're changing the service provider that turns big.info to 220.127.116.11.
One of the reasons you want to change your current DNS Servers could be the servers you are using are not functioning properly. For example if you can go to a website by typing the IP address into your browser's address bar but you can not go to the same website using the domain name this might mean there is a problem with the nameservers you are using.
Another reason to change DNS servers could be the performance. If you find your ISP provided DNS Servers sluggish and slow, you can use some other servers for the job.
Hope this helps.