The Domain Name System (DNS) is a standard technology for managing the names of Web sites and other Internet domains. DNS technology allows you to type names into your Web browser like robority.com and your computer to automatically find that address on the Internet. A key element of the DNS is a worldwide collection of DNS Server. What Is a DNS Server? A DNS server is any computer registered to join the Domain Name System. A DNS server runs special-purpose networking software, features a public IP address, and contains a database of network names and addresses for other Internet hosts.
pwd This command is short for ‘print working directory’, which is exactly what it does. hostname The machine that is currently being worked on is known as the local host. The command ‘netconf’ can be used to change the name of the local host and ‘hostname’ is used to print the local host’s name. whoami As the name suggests, this command prints the user’s login name. id username Unlike the above command, this one prints the user id of the user along with his group id, effective id and all the supplementary groups that are involved.