A server is a computer or device on a network that manages network resources. Servers are often dedicated and they perform only their server tasks.
D (Network and subnet parts) . When using classful IP addressing concepts as described in Chapter 13, Analyzing Subnet Masks, addresses have three parts: network, subnet, and host. For addresses in a single classful network, the network parts must be identical for the numbers to be in the same network.
IP addresses contain four groups of numbers that are separated with periods, and each number group can feature number(s) that range anywhere from 0 - 255. An example of an IP address is 1.123.13.231.