What are Nameservers?

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Nameservers are like the giant phone book of the internet, they keep track of all the website names and their special addresses (IP addresses).  Imagine you're trying to reach a website like www.tierra.net. When you search for the website on your computer, your computer needs to know how and where to find it on the internet. Nameservers tell your computer the IP address for the website you want to visit, and then your computer can connect to the website you want to see. 
Without nameservers, we would have to remember long strings of numbers to visit websites, which would be very hard to do! So, nameservers make it much easier for us to use the internet and find the websites we want to visit.