DNS: Domain Name System. A system of protocols and servers that allow networked applications to look up domain names and retrieve the corresponding IP address for the domain name.
domain name: A name that is assigned within a top-level domain. For example, khanacademy.org is a domain that is assigned within the “.org” top-level domain.
ICANN: International Corporation for Assigned Network Names and Numbers. Assigns and manages the top-level domains for the Internet.
registrar: A company that can register, sell, and host domain names.
subdomain: A name that is created “below” a domain name. For example, “umich.edu” is a domain name and both “www.umich.edu” and “mail.umich.edu” are subdomains within “umich.edu”.
TLD: Top Level Domain. The rightmost portion of the domain name. Example TLDs include “.com”, “.org”, and “.ru”. Recently, new top-level domains like “.club” and “.help” were added.