Pseudo-top-level domains

root is the name of a database record of the root zone in the Domain Name System of the Internet that was occasionally used as a diagnostic marker. Its presence demonstrated the root zone was not truncated upon loading by a root nameserver.

The domain name .local is a special-use domain name reserved by the Internet Engineering Task Force (IETF) so that it may not be installed as a top-level domain in the Domain Name System (DNS) of the Internet. As such it is similar to the other special domain names, such as .localhost. However, .local has since been designated for use in link-local networking, in applications of multicast DNS (mDNS) and zero-configuration networking (zeroconf) so that DNS service may be established without local installations of conventional DNS infrastructure on local area networks.

computer network that is not participating in the world-wide official Domain Name System