Domain name system (DNS) servers maintain a list of IP addresses and corresponding names for all the servers on the Internet. Your computer has to be able to connect to a DNS server in order for you to be able to use the Internet.
Dynamic Host Configuration Protocol (DHCP) is a TCP/IP standard used to dynamically assign IP addresses to computers, so that they can communicate with other network services. A central network server distributes configuration information including IP addresses, DNS servers, subnet mask, and gateways.
Cornell offers a campus-wide DHCP server at no charge.