DNS: DNS stands for Domain Name System. This System translates a domain name such as YourDomain.com into IP numbers. DNS is basically a piece of translation software which allows humans and computers to easily communicate. The network of computers, that constitute the Internet, map domain names to their corresponding IP numbers. The DNS record consists of data similar to the following example: Domain Name: A domain name is the core of your online identity. It is the address web surfers use to find your web site. Your domain name is yours entirely because once registered, no other party may use that identity online in that Top Level Domain.
Primary Nameserver: ns1.ourdnsserver.com(Note: generally when you're changing your DNS at your registrar, there is no need to enter an IP address. This is done for you.)
Primary IP address: 123.456.789.0
Secondary Nameserver: ns2.ourdnsserver.com
Secondary IP Address: 234.567.890.1
Domain Names always have 2 or more parts, separated by periods/dots. The part on the left is YOURDOMAIN (whatever you've chosen), and the part on the right is the extension (com, net, org).
Registrar: The domain registrar is the company that you've actually purchased your domain from. For example, GoDaddy or eNom.