IP (Internet Protocol) is the core of the TCP/IP protocol stack. IP address and Netmask are mandatory parameters for each IP network host. The first parameter is the unique identifier of the computer, the latter directly defines computers in a local network, which can be accessed by this computer. If it is necessary to have an exit to outside network, don't forget to configure the Default gateway parameter.
With DHCP server all the above parameters can be obtained automatically — just check the Use DHCP parameter.
If your computer has several network cards, it may happen that during startup process the kernel would assign the names of the interfaces (eth0, eth1) in a different order. As a result, the interfaces will get wrong settings. In order to prevent this, you can bind the interface to the name either by using hardware address (MAC) or location on the system bus.
There is a number of general network parameters not bound to any specific interface.
Computer name is the name of your computer in a local network. Computer name, unlike the traditional host name in Unix systems (hostname), doesn't contain the network domain name.
Operation and configuration of network services quite often requires using symbolic names of other computers in the network. The system can be configured to transform them to IP addresses either by adding the associations to /etc/hosts file, or using the DNS server (DNS servers field).
Adding the most frequently used domain names (for example, domain) to the Search domains field allows using non-qualified names (computer, instead of computer.domain).