Like its component local-area networks, the Internet permits signals to be transmitted between any two of the millions of computers connect to this internetwork. Clients and Servers Computer networks are designed to permit resource sharing. Functionally, there are two kinds of computers on any network that engages in resource sharing. They have equal status, with no one computer controlling the resources or managing network communications. For more extensive resource sharing over a broader area a server-based network is used.
All networks have rules, or standards, by which communications take place.
These rules govern how messages are broken down into separate pieces, how these pieces are packaged into packets for transmission, how the packets are transmitted, received, and reconstructed, how packets are routed between computers, and how dozens of other technical details of getting information from one computer to another are physically implemented. These sets of rules that govern network communications are called protocols . In order for computers to share or use resources on a network all must have a unique identification a unique network address that can be understood and used by the protocol to forward packets from one computer to the other. Every computer connected to the Internet is assigned an IP address that is unique in the world. Since numbers are difficult to remember, however, IP addresses are normally associated with names as a secondary means of uniquely identifying computers.