The networking words are quite general and work with address specifiers rather than concrete concepts such as host names. There are four types of address specifiers.

Unix domain sockets:

<local> ( path -- addrspec )

Internet host name/port number pairs; the host name is resolved to an IPv4 or IPv6 address using the operating system's resolver:

<inet> ( host port -- inet )

IPv4 addresses, with no host name resolution:

<inet4> ( host port -- inet4 )

IPv6 addresses, with no host name resolution:

<inet6> ( host port -- inet6 )

While the inet addressing specifier is capable of performing name lookups when passed to <client>, sometimes it is necessary to look up a host name without making a connection:
resolve-host ( addrspec -- seq )