Networks may be classified according to a wide variety of characteristics, such as the mediumused to transport the data, communications protocol used, scale, topology, and organizational scope.
Communications protocols define the rules and data formats for exchanging information in a computernetwork, and provide the basis for network programming. Well-known communications protocols include Ethernet, a hardware and link layer standard that is ubiquitous in local area networks, and theInternet protocol suite, which defines a set of protocols for internetworking, i.e. for data communication between multiple networks, as well as host-to-host data transfer, and application-specific datatransmission formats.
Computer networking is sometimes considered a sub-discipline of electrical engineering, telecommunications, computer science, information technology or computer engineering,since it relies upon the theoretical and practical application of these disciplines.
Before the advent of computer networks that were based upon some type of telecommunications system,communication between calculation machines and early computers was performed by human users by carrying instructions between them. Many of the social behaviors seen in today's Internet were demonstrablypresent in the 19th century and arguably in even earlier networks using visual signals.
• In September 1940, George Stibitz used a Teletype machine to send instructions for a problem set from his...