Sometimes just the leftmost part of such a domain name, as in akasha. The authority for a domain can create subdomains however it likes. A domain server may also provide other information about a domain. Every registered domain must have at least two domain servers. The domain servers running in the Internet, together with the protocols and formats that they use, and the set of domains that they serve.
Domain names are easy for humans to use.
The Internet protocols actually use IP addresses to route data. Domain servers translate from domain names to IP addresses.