Stands for Domain Name System and is responsible for translating domain names into IP addresses. When you enter a URL into your browser, your computer will send the domain name to a DNS server. The DNS server responds with the IP address (eg 192.168.0.100). Your computer uses the IP address to connect to the web server.
The DNS servers are organized in a hierarchical structure.
At the top is the root. Followed by the top-level domain (TLD) servers, for top-level domains such as: .com .org etc
Next is the second level domain servers for individual domain names: elluminetpress.com
Below is the subdomain: shop.elluminetpress.com