Host names

A host, or web site, on the Internet is identified by a host name, such as www.example.com. Host names are sometimes called domain names. Host names are mapped to IP addresses, but a host name and an IP address do not have a one-to-one relationship.

A host name is used when a web client makes an HTTP request to a host. The user making the request can specify the IP address of the server rather than the host name, but that is now unusual on the Internet. Host names are more convenient for users than numeric IP addresses. Companies, organizations, and individuals frequently choose host names for their web sites that can be easily remembered by users.

Host names are mapped to IP addresses by a server known as a DNS server or domain name server. In a large network, many DNS servers collaborate to provide the mapping between host names and IP addresses.