DNS is short for Domain Name System, and this system translates domain names into IP addresses and controls email delivery. It's very hard for us to remember complex IP addresses but DNS has made it possible for us to use domain names instead of IP addresses.

DNS is a sort of like the white pages directory of the internet. When you put a domain name into your browser, DNS does the directory lookup to seek to which server the domain is indicated and what its IP address is and then it responds by showing the site you requested.