All entities in a data communications network must be uniquely identified to allow data to be directed to the intended recipient. Each node is usually allocated at least one address.
Most users are able only to remember a few numbers but are able to memorise entire lists of words.
An email address is a name, as is a free-phone number. To use a name, it is first necessary to find the corresponding numeric address, this is usually performed by a name-server, which is a network resource which has a list of all names and the corresponding addresses. A name server provides a service which resolves a name into an address. A network provides the connections between two types of node. Some nodes provide both functions and may be called by either name, depending upon which function they perform.